Ptha 2431 - Management Of Neurological Disorders - Martin And Kessler Book And Miele Lecture - Exam 1

Front 1

What are the two ANATOMICAL divisions of the nervous system? ***

Back 1

- central nervous system (CNS)

- peripheral nervous system (PNS)

Front 2

What comprises the CNS? ***

Back 2

- brain

- spinal cord

Front 3

What comprises the PNS? ***

Back 3

- everything except the brain and spinal cord

- THIS INCLUDES THE CRANIAL NERVES!!

Front 4

What protective tissue surrounds the brain? ***

Back 4

meninges

(dura mater, arachnoid, pia mater)

Front 5

What fluid flows through ventricles in the brain? ***

Back 5

cerebral spinal fluid (CSF)

Front 6

What is the general function of the brain? ***

Back 6

receives (via white matter) and processes (within gray matter) sensory information for motor performance

Front 7

Of what tissue is white matter comprised? ***

Back 7

myelinated axons

Front 8

Of what tissue is gray matter comprised? ***

Back 8

neuronal cell bodies and dendrites

Front 9

What are the major components of the brain? ***

Back 9

- cerebrum
- cerebellum
- brain stem (midbrain, pons, medulla oblongata)

Front 10

What are the components of the brain stem? ***

Back 10

- midbrain
- pons
- medulla oblongata

Front 11

What is the function of the brain stem? ***

Back 11

- direct continuance of spinal cord cranially

- link between spinal cord, cerebellum, cerebrum

- gives rise to cranial nerves (which are part of the PNS!!)

Front 12

What is the function of the cerebellum? ***

Back 12

- coordinating skilled voluntary movements (e.g., enabling you to touch your nose gently, vice hit yourself in nose)
- integrating, coordinating, and executing multijoint movements

- regulating initiation, timing, sequencing, and force generation of muscle contractions
- sequencing order of muscle firing when a group of muscles work together to perform a movement

- comparing actual motor performance with that which is anticipated
- controlling balance and equilibrium

Front 13

What is the function of the cerebrum? ***

Back 13

- center for highest mental functions

- two cerebral hemispheres make up largest part of brain, or the uppermost portion

- hemispheres control opposite sides of body's major structures

Front 14

What structures comprise the cerebrum? ***

Back 14

- cerebral cortex (gray matter)
- subcortical white matter fiber tracts

- thalamus
- hypothalamus

- basal ganglia
- corpus callosum

Front 15

Name the lobes of the cerebrum. ***

Back 15

- frontal lobe
- parietal lobe
- temporal lobe
- occipital lobe

Front 16

Where is the motor speech area of Broca located? ***

Back 16

frontal lobe, left hemisphere

Front 17

What is the corpus callosum? ***

Back 17

- a wide, flat bundle of neural fibers beneath the cortex
- largest white matter structure in the brain

- connects the left and right cerebral hemispheres
- facilitates interhemispheric communication

Front 18

What pathology is associated with cell death within the substantia nigra? ***

Back 18

Parkinson's Disease

(the death of dopamine-producing cells)

Front 19

Is the spinal cord also protected by meninges? ***

Back 19

yes, the same as the brain

(dura mater, arachnoid, pia mater)

Front 20

Describe the central canal of the spinal cord. ***

Back 20

- narrow central canal through the center of the spinal cord

- filled with CSF

- disappears by adulthood except at cervical levels

Front 21

What is the function of the spinal cord? ***

Back 21

- communication link between brain and PNS (body)

- pathway for sensory (afferent) information from PNS to brain (receptor…nerve…spinal cord…brain)

- pathway for motor (efferent) info from brain to PNS (brain…spinal cord…nerve…glands/muscles)

Front 22

What comprises the spinal cord? ***

Back 22

groups of neurons in the form of fiber bundles (tracts, fasiculi, columns, funiculi—bundles of axons/fibers)

Front 23

What comprises the PNS? ***

Back 23

- formed by the nerves leading to and from CNS

- nerves contain nerve fibers that conduct afferent/efferent information to/from CNS

- contains cranial nerves (12 pair) and spinal nerves (31 pair)

Front 24

What are the FUNCTIONAL divisions of the nervous system? ***

(PNS)

Back 24

- Autonomic (visceral) Nervous System (ANS)

- Somatic (body) Nervous System (SNS)

(these divisions are composed of both CNS and PNS components)

Front 25

What is the function of the ANS? ***

Back 25

- innervates smooth muscles and glands, blood vessels

- relays sensory/motor information

- involuntary

Front 26

What is the function of the SNS? ***

Back 26

- innervates muscles, skin, joints, mucous membranes

- relays sensory/motor information

- voluntary

Front 27

What is a neuron? ***

Back 27

- specialized cell of nervous system

- functional unit of nervous system

Front 28

What are the three basic components of a neuron? ***

Back 28

- cell body
- dendrite
- axon

Front 29

What is the structure and function of a neuronal cell dendrite? ***

Back 29

- many threadlike projections radiating from cell body

- receptive part of neuron
- receives information from the environment or other neurons and transmits that information toward the cell body, where it is processed

Front 30

What is the structure and function of a neuronal cell axon? ***

Back 30

- single tubular extension of cell membrane comprised of many neurofilaments
- length varies from one millimeter to one meter

- most neuronal axons are myelinated (wrapped in concentric layers of fatty white substance called myelin) which serves to protect and insulate axon and enhance speed of electrical conduction

- branches at terminal end (sometimes 2-300 times)

- transports cellular materials to/from terminal endings
- conducts information (in form of action potentials) away from cell body to target cells such as muscle cells, glands, or other neurons

Front 31

How do neurons differ from other cells of the body? ***

Back 31

- they are specialized for conduction of electrical impulses which transmit information (afferent/efferent) within the nervous system

- they require a constant supply of glucose and oxygen from arterial blood supply

- they do not multiply, and have little to no regeneration potential

Front 32

Which types of nerve fibers conduct motor (efferent) impulses? ***

Back 32

A

Front 33

Describe gray matter. ***

Back 33

- nervous tissue composed of dense collections of nerve cell bodies (grayish in color);

- comprise the cerebral cortex (outer layer of cerebrum) and innermost portion of spinal cord

Front 34

Describe white matter. ***

Back 34

- areas of nervous tissue in CNS composed of myelinated axons (glistening white color due to fat content) that carry information away from cell bodies

Front 35

What structures/tissues comprise white matter? ***

Back 35

- tracts/funiculi (vertical projections – spinal cord)

- association fibers (within hemispheres)

- commissure fibers (between hemispheres; e.g., corpus callosum)

Front 36

What structures/tissues comprise gray matter? ***

Back 36

- nuclei: nerve cells with a common function; grouped together; within CNS

- ganglia: nerve cells with common function: grouped together; outside of CNS (usually) (e.g., dorsal root ganglia)

Front 37

What is the primary function of neurons? ***

Back 37

transmission of information to other nerve cells (neurons) muscle cells, or glandular cells

Front 38

Describe the general route of transmission of nerve impulses. ***

Back 38

- stimulation of sensory neurons (from either internal or external environment)
- reception by sensory neurons

- transmission (conduction of impulse) to CNS
- integration (processing) of info by CNS & decision is made
- transmission (conduction of impulse) to PNS

- response by effector (muscle contraction, glandular secretion)

Front 39

The human nervous system is a three-neuron system. List the three types and describe each. ***

Back 39

- sensory (afferent) neuron - carries information from environment to brain (dorsally)

- motor (efferent) neuron - carries information from brain to environment/effector (ventrally)

- interneuron - between sensory/motor neurons, increase ability of NS to process/modify responses – higher level of mental/motor function

Front 40

If the nervous system is the communication system of the body, how is that communication carried out between neurons? ***

Back 40

- occurs as a result of transmission of electrical impulses between neurons

- transmission of impulse occurs as a result of the electrical properties of the neuron's cell membrane

Front 41

What chemical elements are found inside/outside the neuronal cell membrane? What purpose do they serve? ***

Back 41

- cell membrane separates extracellular fluid from intracellular fluid (Na+ & Cl- outside; K+ and proteins inside)

- cell membrane actively maintains a difference in ionic concentrations on either side; (inside slightly negative (K+ and anions) (outside slightly positive (Na++)

- difference in charge = biological battery = polarization

Front 42

What does "polarization" of a nerve cell mean? ***

Back 42

it means the membrane exhibits the potential to do work (exhibits excitability)

Front 43

What does "excitability" mean with respect to nerve cells? ***

Back 43

it means the membrane has the potential to conduct electrical impulses

Front 44

What is the RMP of a nerve cell? ***

Back 44

- the resting membrane potential

- the actual negative voltage across membrane of resting cells

- (-70mV inside cell membrane; depending on K+ concentration)
(other sources say -65mV)

Front 45

Describe the propagation of an action potential. ***

Back 45

- depolarizing current passively spreads down the axon, causing the interior of the axon to become more positive than when the membrane is resting

- in the adjacent membrane, when the depolarizing current reaches threshold level, Na+ channels open, causing rapid depolarization of the membrane

- an action potential is generated, and the depolarizing current continues to propagate down the axon

Front 46

From what stimuli may excitation of a neuronal cell membrane result? ***

Back 46

- mechanical (pressure)
- electrical
- chemical (neurotransmitter)

Front 47

What two states may be created by changes in polarity of a nerve cell? ***

Back 47

- depolarization – inside of cell membrane becomes more positive, increasing membrane excitability

OR

- hyperpolarization – inside of cell membrane becomes more negative, decreasing membrane excitability/increasing inhibition

Front 48

If depolarization of a nerve cell is sufficient, a(n) ______ ______ is created. ***

Back 48

action potential

Front 49

What is an action potential? ***

Back 49

a stereotyped electrical message that passes along the axon from cell body to terminal branches (synapse)

Front 50

In what manner is a portion of an action potential relayed? ***

Back 50

- it isn't

- action potentials are all or nothing impulses

Front 51

Which of the following variable(s) may be changed in the transmission of an action potential? (For example, to indicate increased urgency of the stimulus.) ***

- amplitude?
- duration?
- conduction velocity?

Back 51

- amplitude and duration are always the same for any given type of neuron (no variation of strength), but

- conduction velocity (speed of transmission) can vary, depending on the type of axon

Front 52

How does diameter of the fiber affect transmission of action potentials? ***

Back 52

- smaller diameter - slower propagation of action potential

- larger diameter - faster propagation of action potential

Front 53

How does myelination (or lack thereof) of the fiber affect transmission of action potentials? ***

Back 53

- unmyelinated axon - slower propagation

- myelinated axon - faster propagation (up to 50 times faster)

Front 54

How are nerve cell axons myelinated in: ***
- the CNS?
- the PNS?

Back 54

- oligodendrocytes

- Schwann cells

Front 55

What are the nodes of Ranvier? ***

Back 55

interruptions (gaps) between the myelin sheaths covering the axon

Front 56

Describe saltatory conduction. ***

Back 56

- electrical impulses depolarize only at nodes of Ranvier instead of along the entire axonal membrane

- action potentials “jump” from node to node

- this increases the conduction velocity of the action potential

- this means of conduction is both faster and more energy efficient than via the unmyelinated method

Front 57

How does multiple sclerosis affect myelin? ***

Back 57

- it is a demyelinating disease that affects areas of the CNS (spinal cord, brainstem, cerebellum, cerebrum)

- apparent (?) viral response whereby myelin is destroyed and replaced by plaque

- loss of myelin impairs neuronal function, disrupting transmission of electrical impulses

- clinical presentation depends on area affected (can cause visual impairment, spasticity, paresthesias, decreased coordination, loss of motor function)

Front 58

What is a synapse? ***

Back 58

- a point of functional communication between two neurons; a junction between two neurons

- space between the axon of one neuron and the dendrite of the next neuron

Front 59

What are the three components of a synapse? ***

Back 59

- presynaptic neuron/membrane
- synaptic cleft
- postsynaptic neuron/membrane

Front 60

What is a synaptic cleft? ***

Back 60

a tiny gap between neurons (which do not actually touch) of approximately 20 - 30 nanometers, 10-9 mm, or one millionth of an inch

Front 61

What is a presynaptic neuron/membrane? ***

Back 61

- a neuron/membrane whose branches terminate at the synapse

- ends of branches at synaptic region (synaptic knobs/axon terminals) contain vesicles filled with neurotransmitter which, on signal of action potential, are released into the synaptic cleft

Front 62

What is a postsynaptic neuron/membrane? ***

Back 62

- a neuron whose receptor begin at the synapse

- receives neurotransmitter at receptor sites (although it may or may not pick it up)

Front 63

How does neuron to neuron transmission across the synapse function? ***

Back 63

- an electrical impulse in the form of an action potential travels along the axon of the presynaptic neuron until it reaches the axon terminal

- vesicles in the axon terminal of the presynaptic neuron release the appropriate neurotransmitters into the synaptic cleft

- the neurotransmitters travel across the synaptic cleft to receptor sites specific for that neurotransmitter on the postsynaptic neuron

- the neurotransmitter can be either excitatory or inhibitory depending on the neurotransmitter; can lead to either depolarization or hyperpolarization of postsynaptic membrane

- (electrical... chemical... electrical transmission)
- (action potential... neurotransmitter... action potential)

Front 64

How does a single neuron handle excitatory and/or inhibitory potentials from thousands of other neurons? ***

Back 64

the response of the target neuron is determined by the net effect of all the incoming potentials

Front 65

Describe the effects of the following neurotransmitters: ***
- acetylcholine
- norepinephrine
- dopamine
- serotonin, endorphins, enkephalins
- gamma-aminobutyric acid (GABA)

Back 65

- excitatory to muscle cells
- excitatory or inhibitory, depending on location
- primarily inhibitory
- primarily inhibitory
- primarily inhibitory

Front 66

What happens to neurotransmitters not taken up by the postsynaptic membrane? ***

Back 66

they are:
- immediately reabsorbed by the presynaptic membrane, or
- broken up by enzymes

Front 67

Is the CNS mainly excitatory or inhibitory? ***

Back 67

inhibitory

- with hundreds of thousands of interconnecting neurons/synapses … under normal circumstances, majority of these connections must be inhibited…if not, nervous system would overload and short circuit.

For example:
1) strychnine inhibits inhibitory responses (double negative - it stops inhibitory response, thus causes convulsions)
2) Parkinson’s is due to lack of inhibitory NT dopamine (rigidity).

Front 68

How does neuron to muscle cell transmission of action potentials function? ***

Back 68

- axon of one motor neuron branches hundreds of times on hundreds of individual muscle cells/fibers of a muscle

- each axonal branch innervates a single muscle cell

- action potential arrives at the presynaptic membrane and stimulates release of neurotransmitter (acetylcholine--ACh)

- the neurotransmitter crosses the synapse to the postsynaptic membrane of the muscle fiber and attaches to ACh receptor sites

- muscle fiber membrane depolarizes and fires an action potential to muscle fiber = contraction of muscle fiber

- all muscle fibers innervated by that one neuron will contract at once = all or none response (all acting as part of the motor unit)

Front 69

What is a motor unit? ***

Back 69

a single motor axon/alpha motor neuron and all the muscle fibers (cells) it innervates

Front 70

What is the neuromuscular junction? ***

Back 70

the synaptic region between the axonal presynaptic membrane and the muscle fiber

Front 71

What is the motor end plate? ***

Back 71

a specialized area of muscle post-synaptic membrane and muscle fiber

Front 72

List some examples/causes of neuromuscular junction dysfunction secondary to ACh reception dysfunction. ***

Back 72

- curare (South American vegetable extract) used on hunting darts to paralyze animals; competes with Ach for receptors on postsynaptic membrane; no muscle contractions... can’t breathe... death

- Myasthenia Gravis - disease wherein body produce antibodies which cover Ach receptor sites on postsynaptic membrane … rapidly occurring muscle weakness with activity

Front 73

Name some commonly used medications that inhibit excessive stimuli. ***

Back 73

- mehylpenidate hydrochloride (Ritalin) - treatment of attention deficit disorders in children > 6 years old, also symptomatic management of narcolepsy

- clonidine (Catapres) - management of mild to moderate hypertension; either used alone or in combination with other antihypertensive

- bupropion (Wellbutrin) - treatment of depression

- buspirone hydrochloride (BuSpar) - management of anxiety

Front 74

What is neural integration? ***

Back 74

- process of sorting, interpreting, and integrating incoming signals and determining an appropriate response

- occurs at the neuronal cell body level

- 90% of neuronal cell bodies are in CNS (brain and spinal cord)

- therefore, CNS is the integration center for the nervous system.

Front 75

Since the majority of neuronal cell bodies are in the CNS, the CNS is the ______ center for the nervous system. ***

Back 75

integration

Front 76

Ninety percent of neuronal cell bodies are located in the ____. ***

Back 76

CNS (brain and spinal cord)

Front 77

Describe the external anatomy of the spinal cord. ***

Back 77

- located in the vertebral canal, surrounded by CSF

- approx. 42-45 cm long (1.5ft); 2/3 length of vertebral column; terminates at approximately L1

- slender cylinder slightly less than 1in. diameter; width varies with slight expansions in Cx (C3-T2) and Lx (L1-S3) regions due to plexuses, origins of nerves and UE and LE at these regions and larger numbers of cell bodies

- continuous with brain stem (medulla oblongata (inside foramen magnum)

- tapers to conus medullaris caudally (inferiorly); below conus medullaris, lumbar and sacral spinal roots descend in a bundle and exit at respective vertebral segmental levels; bundle of spinal nerves is called the cauda equina

- divided into approximately 30 segments: 8 cervical, 12 thoracic, 5 lumbar, 5 sacral and ? coccygeal)

Front 78

The terminal end of the spinal cord is called the ______ _____. ***

Back 78

- conus medullaris (at around L1)

- composed of sacral spinal segments

Front 79

Below the conus medullaris, the bundle of lumbar and sacral spinal roots is called the _____ _____. ***

Back 79

- cauda equina

- comprised of nerve roots for spinal nerves L2 through S5

Front 80

The terminal thread that attaches the conus medullaris to the coccyx is called the _____ _______. ***

Back 80

filum terminale

Front 81

How are the segments of the spinal cord divided? ***

Back 81

there is no definitive dividing line, rather a blending of segments

Front 82

How many spinal nerves are there? ***

Back 82

at each segmental level are a pair of exiting spinal nerves (31 pairs)

Front 83

How do the spinal cord segments correspond to the vertebral segments? ***

Back 83

spinal cord segments do not necessarily correspond to vertebral segments

Front 84

What structures divide the spinal cord into right and left halves? ***

Back 84

- anterior median fissure (deep fold containing blood vessels)

- posterior median sulcus

Front 85

List the membranes surrounding the spinal cord. ***

Back 85

- same three membranes (meninges) that surround the brain, as they are continuous

- externally to internally:
---- dura mater
---- arachnoid (mater)
---- pia mater

Front 86

What is the dura mater of the spinal cord? ***

Back 86

- tough outer membrane

- outer layer attaches to bony vertebral column, inner layer forms a dural sac around spinal cord

Front 87

What is the arachnoid of the spinal cord? ***

Back 87

- middle layer closely associated with dura

- thin, transparent, CSF circulates in subarachnoid space

Front 88

In which space does the CSF circulate around the outside of the spinal cord? ***

Back 88

subarachnoid

(also, to a degree in the central canal, although most of this closes off by adulthood--still may be some at the cervical level)

Front 89

What is the pia mater of the spinal cord? ***

Back 89

the innermost layer that closely surrounds the spinal cord

Front 90

What can extradural, intradural, or epidural masses (tumors, infections, hematomas) cause within the vertebral column? ***

Back 90

displacement of, or abnormal pressure on the spinal cord

Front 91

By which vessels is the spinal cord vascularized? ***

Back 91

arterial circulation:
- subclavian artery (branch of aorta)
- vertebral artery--ascends to brain and descends to spinal cord, and splits into:
---- anterior spinal artery and
---- posterior spinal artery, both of which have many branches around the entire spinal cord, forming a ring of arteries (arterial corona)

venous drainage:
- veins located in the epidural and subarachnoid spaces ultimately drain into the venae cavae

Front 92

What is the arterial corona of the spinal cord? ***

Back 92

- a ring of arteries that surrounds the spinal cord

- formed by the split of the vertebral artery into the anterior and posterior spinal arteries and their many branches

Front 93

What are the clinical implications of impaired circulation to the spinal cord? ***

Back 93

- occlusion of artery (thrombus) can deprive nervous tissue of blood supply and result in cell death and SC damage

- arterial rupture (hemorrhage) can result in epidural/intradural hematomas and pressure onspinal cord with possible cell death; more common in elderly with hyperextension injuries (anterior spinal artery)

Front 94

What structures comprise the spinal nerves? ***

Back 94

a ventral root and a dorsal root comprise each spinal nerve

Front 95

How many spinal nerves are there? ***

Back 95

31 pairs

Front 96

Where do the spinal roots exit the vertebral column? ***

Back 96

at the intervertebral foramina

Front 97

Describe the dorsal root of the spinal cord. ***

Back 97

- contains axonal fibers which are transmitting sensory (afferent) information from the somatic and visceral (autonomic) systems

- conveys sensory information from skin, joints, muscles, and viscera

- each dorsal root contains a dorsal root ganglia (DRG) which contains cell bodies of the sensory axons from the periphery

- roots join in vertebral canal and pass out of it via intervertebral foramen

Front 98

What is a dorsal root ganglion? ***

Back 98

a nodule on a dorsal root that contains cell bodies of neurons in afferent spinal nerves

Front 99

Once the dorsal and ventral nerve roots pass through the intervertebral foramen they merge to form spinal nerves which convey.... ***

Back 99

both sensory (afferent) and motor (efferent) information

Front 100

Shortly after the dorsal and ventral roots merge to form the spinal nerve, the spinal nerve splits into.... ***

Back 100

two primary branches (rami)

Front 101

What portions of the body do the anterior rami innervate? ***

Back 101

- limbs
- anterior/lateral trunk
- branch to ANS

- intercostal muscles
- muscles and skin in the extremities

Front 102

What portions of the body do the posterior rami innervate? ***

Back 102

posterior trunk

- paravertebral muscles
- posterior aspects of the vertebrae, and the
- overlying skin

Front 103

Describe the sensory and motor functions of the spinal nerve. ***

Back 103

(see picture)

- vertical dotted line indicates division between CNS and PNS
- blue spiral in muscle indicates muscle spindle receptor
- blue triangle in muscle indicates Golgi tendon organ
- red "V"s indicate motor endings in muscles

Front 104

Describe a dermatome. ***

Back 104

(see picture)

- region of skin innervated by afferent nerve fibers of a single spinal nerve

- lesions at any particular spinal nerve level result in sensory impairment along the dermatomal region
(e.g., C6 spinal nerve compression – sensory deficits to radial forearm/thumb; L5 spinal nerve compression – sensory deficits from anterior/lateral leg to dorsum of foot)

* due to overlapping of dermatomes the areas of innervation tend to vary by author

Front 105

What is a myotome? ***

Back 105

- a group of muscles partially innervated by a single spinal nerve (efferent nerve fibers)

(e.g., myotome for C5: scapular muscles, deltoid
C6: elbow flexors, wrist extensors
L2: hip flexors
L3: knee extensors
S1: hip extensors, knee flexors, plantar flexors)

Front 106

Dermatomes are ______ and myotomes are _______. ***

(sensory or motor)

Back 106

- sensory/afferent

- motor/efferent

Front 107

A lesion of a single spinal nerve is usually associated with _____ ______ but not paralysis. ***

Back 107

muscle weakness (paresis) because the system of innervation has some inherent redundancy

(e.g., L3 spinal nerve compression = weakness of quadriceps, but L2 and L4 can ensure some function remains)

Front 108

How many spinal nerves make up a dermatome? ***

Back 108

one

Front 109

A lesion of a spinal nerve of a particular dermatome causes ______ impairment. ***

Back 109

sensory

Front 110

What muscle group(s) does the C6 myotome innervate? ***

Back 110

- elbow flexors

- wrist extensors

Front 111

What muscle group(s) does the L2 myotome innervate? ***

Back 111

hip flexors

Front 112

What muscle group(s) does the L3 myotome innervate? ***

Back 112

knee extensors

Front 113

What muscle group(s) does the S1 myotome innervate? ***

Back 113

- hip extensors
- knee flexors
- plantar flexors

Front 114

What muscle group(s) does the C5 myotome innervate? ***

Back 114

- scapular muscles

- deltoid

Front 115

Describe the internal anatomy of the spinal cord. ***

Back 115

longitudinal columns of gray (central) and white matter throughout length of spinal cord

Front 116

Describe the central gray matter of the spinal cord. ***

Back 116

- cell bodies -- shaped like a butterfly (or letter "H") in most spinal cord areas (remember the gray matter is masses of cell bodies)

- anterior (ventral) horn -- contains lower motor neuronal cell bodies (alpha and gamma motor neurons); axons exit through ventral root

- (intermedio)lateral horn -- present between T1 and L2 levels; neurons for ANS--specifically cell bodies for preganglionic sympatheic neurons; axons exit through ventral root; responsible for processing autonomic information

- posterior (dorsal) horn -- sensory neuronal cell bodies synapsing with DRG axons in dorsal root

- central gray matter is laminated (layers of nerve cells) with specific types of cell bodies in certain layers (see picture)
---- laminae I - VII primarily sensory neuron cell bodies
---- laminae VIII & IX primarily motor neuron cell bodies

Front 117

The anterior and posterior gray matter horns are larger in the cervical and lumbar regions of the spinal cord due to.... ***

Back 117

innervation of the UE and LE

Front 118

Describe the peripheral white matter of the spinal cord. ***

Back 118

(see picture)

- peripheral bundles of axons (myelinated and unmyelinated) which surround central gray horn areas

- ascending tracts transmit sensory information to brain from PNS (afferent info)

- descending tracts transmit motor information from brain to PNS (efferent info)

- specific bundles (tracts/columns) have similar origins and destinations, carry common info, and have common functions

Front 119

How are the tracts/bundles of peripheral white matter organized? ***

Back 119

- the majority of tracts/bundles exhibit somatotopic* organization with fibers arranged in an orderly fashion from medial to lateral (usually, UE more medially, LE more laterally located)

* point-for-point correspondence of an area of the body to a specific point on the central nervous system (like the homunculus)

Front 120

Describe the corticospinal tract. ***

Back 120

(see picture)

- descending motor (efferent) tract/primary motor tract
- pyramidal system (crosses in brain stem)

- transmits motor information from cerebral cortex (primary and premotor cortices) to spinal cord
- main tract for nearly all volitional muscle activity/skilled movements

- monosynaptic (at anterior horn cells)

Front 121

How is the corticospinal tract referred to in the brain stem with respect to cranial nerves? ***

Back 121

corticobulbar tract

Front 122

Trace the descending path of a motor response along the pyramidal motor system's corticospinal tract.

(Need to be able to do this for the test!!) ***

Back 122

UMNs
- from neuronal cell bodies in cerebral cortex (gray matter) via myelinated fibers to the
- brainstem, then
- pyramidal decussation at the medulla oblongata (where 80-90% of fibers cross to the contralateral side—the other 10-20% remain in the medial corticospinal tract), then
- down through the spinal cord in the lateral column, where
- at each spinal cord level (segment), designated axons enter gray matter of ventral (anterior) horn and synapse on anterior horn cells with

LMNs
- consisting of alpha motor neurons (for muscle fibers) and gamma motor neurons (for muscle spindles)
- then the efferent axons exit the spinal cord via the ventral root,
- pass through the spinal nerve,
- into the plexus
- via the peripheral nerve
- to the muscle

Front 123

What is the result of a lesion at any point along the corticospinal tract? ***

Back 123

loss of motor response below the level of the lesion

(so if the lesion is above the medulla oblongata, the effect would be seen on the opposite side)

Front 124

What would be the result of a lesion at a point on the corticospinal tract above the medulla oblongata? ***

Back 124

loss of motor response on the contralateral side

Front 125

What is the Nagi model used to describe?

Back 125

the relationship between health and function

Front 126

Do impairments necessarily result in functional limitations or disabilities?

Back 126

no, they may or may not

if someone is still able to perform ADLs and meet their age-specific expectations there is no functional limitation or disability

progression is not inevitable either

Front 127

What is "buffering the disablement process"?

Back 127

preventing impairment, functional limitation, or disability by identifying disablement risk factors that may impede patient functioning and interrupting the progression

Front 128

What is the Guide's definition of function?

Back 128

- activities identified by an individual as essential to support physical, social, and psychological well-being and to create a personal sense of meaningful living

- it is related to age-specific roles in a given social contexts and physical environment

Front 129

What factors define an individual's functional performance?

Back 129

personal characteristics such as:
- physical ability
- emotional status
- cognitive ability
- environment in which person functions
- social expectations placed on the person's performance by family, the community, or society in general

Front 130

What is a handicap?

Back 130

the societal disadvantage of disability

Front 131

Besides personal characteristics, environment, and social expectations, what else can affect the disablement process?

Back 131

individual factors such as:
- congenital disorders
- genetic predisposition to disease
- demographics (age, sex, educational level, socioeconomic status)
- comorbidities
- lifestyle choices
- health habits
- environmental factors (including access to medical and rehab care and physical and social environments)

Front 132

What should the PT consider before delegating interventions to the PTA?

Back 132

- knowledge, skills, and abilities of the PTA

- whether the intervention requires immediate and continuous examination and evaluation of the patient (per APTA, these interventions are to be performed exclusively by the PT)
- patient's condition (stability, acuity, criticality and complexity)

- practice setting
- type of intervention
- patient's probable outcome
- restrictions imposed by patient's insurance

Front 133

When may interventions for pediatric patients be delegated to PTAs? When may they not?

Back 133

- under the direction and supervision of a PT

- when the child is physiologically unstable, or the child's condition requires multiple adjustments of sequences and procedures due to rapidly changing physiologic status and/or response to treatment

Front 134

What are the PT responsibilities in the examination phase?

Back 134

- obtain patient history
- perform systems review
- select and administer tests and measures
- identify issues that require consultation with or referral to another provider

Front 135

What are the PT responsibilities in the evaluation phase?

Back 135

- use data from examination to make clinical judgments
- identify issues that require consultation with or referral to another provider

Front 136

What are the PT responsibilities in the diagnosis phase?

Back 136

- interpret evaluation/examination data
- organize data into clusters, syndromes, categories
- determine prognosis and POC
- plan the most appropriate intervention strategies

Front 137

What are the PT responsibilities in the prognosis phase?

Back 137

- determine level of optimal improvement expected from interventions
- assess amount of time required to reach optimal improvement
- document POC specifying interventions to be used, timing, and frequency

Front 138

What are the PT responsibilities in the intervention phase?

Back 138

- apply purposeful and skilled interaction with patient/client and, if appropriate, with other individuals involved in patient's/client's care
- use various physical therapy methods to produce changes in patient's/client's condition consistent with the diagnosis/prognosis
- assess the patient/client for new clinical findings or lack of progress
- reexamine the patient's/client's status to determine changes and modify or redirect intervention

Front 139

The brain, brain stem and spinal cord are composed of two basic types of nerve cells called _______ and _____.

Back 139

- neurons

- neuroglia

Front 140

What are the three subtypes of neurons?

Back 140

- afferent neurons (sensory)
- interneurons (connectors)
- efferent neurons (motor)

Front 141

What is another name for a neuronal cell body?

Back 141

soma

Front 142

Name of the interface between:
- neuron and neuron
- neuron and muscle fiber
- neuron and gland

Back 142

- synapse
- neuromuscular junction
- neuroglandular junction

Front 143

Which neurotransmitter is used by all neurons that synapse with muscle fibers?

Back 143

acetylcholine (ACh)

Front 144

Myelinated axons are bundled together within the CNS to form ______ _____.

Back 144

fiber tracts

Front 145

What is the surface of the cerebrum called?

Back 145

cerebral cortex

Front 146

What are the depressions (valleys) of the cerebral cortex called? The ridges?

Back 146

- sulcus (pl. sulci)

- gyrus (pl. gyri)

Front 147

What is the purpose of the gyri and sulci of the cerebral cortex?

Back 147

they increase the surface area of the cerebrum without requiring an increase in the size of the brain

Front 148

List the layers and spaces of the meninges, outermost to innermost.

Back 148

- epidural space
- dura mater
- subdural space
- arachnoid
- subarachnoid space
- pia mater

Front 149

What is the "sidedness" of brain function called?

Back 149

- hemispheric specialization
or
- lateralization

Front 150

The frontal lobe is frequently referred to as the ______ ______ _______.

Back 150

primary motor cortex

Front 151

For what functions is the frontal lobe responsible?

Back 151

- voluntary control of complex motor activities
- cognitive functions (judgment, attention, awareness, abstract thought, mood, aggression)

- Broca's area - principal motor region for speech
(left hemisphere - plans movements of the mouth,
right hemisphere - nonverbals, such as gestures and adjustment of tone)

(motor input is mapped via the motor homunculus)

Front 152

For what functions is the parietal lobe responsible?

Back 152

- primary sensory cortex
- perception (attaching meaning to sensory information)

(sensory input is mapped via the sensory homunculus)

Front 153

For what functions is the temporal lobe responsible?

Back 153

- primary auditory cortex
- visual perception
- musical discrimination
- long-term memory

(Wernicke's area allows hearing and comprehension of spoken language)

Front 154

For what functions is the occipital lobe responsible?

Back 154

- primary visual cortex
- organizes, integrates, and interprets visual information

Front 155

What are association areas within the brain?

Back 155

regions within the parietal, temporal, and occipital lobes that horizontally link different parts of the cortex

(e.g., sensory association cortex integrates and interprets information from all the lobes receiving sensory input and allows individuals to perceive and attach meaning to sensory experiences

Front 156

What are some additional functions of the association areas?

Back 156

- personality
- memory
- intelligence (problem solving and comprehension of spatial relationships)
- generation of emotions

Front 157

The primary motor cortex of the frontal lobe is primarily responsible for....

Back 157

contralateral voluntary control of upper extremity and facial movement

Front 158

The premotor area of the frontal lobe is primarily responsible for....

Back 158

- controlling muscles of the trunk and

- anticipatory postural adjustments

Front 159

The supplementary motor area of the frontal lobe is primarily responsible for....

Back 159

- initiation of movement
- orientation of eyes and head
- bilateral, sequential movements

Front 160

Which hemisphere of the brain is considered the dominant hemisphere in an individual?

Back 160

- the one responsible for language

- thus, approximately 95% of the population (including all right-handed individuals) are left-hemisphere dominant

(even 50% of left-handed individuals are left-hemisphere dominant)

Front 161

What are the functions of the left hemisphere of the brain?

Back 161

verbal/analytic side

- cognitive style --- processing information in a sequential, organized, logical, and linear matter for thorough analysis

- perception/cognition --- language processing and producing for most people (specifically frontal and temporal lobes)

- academic skills --- recognizing and comprehending written words (parietal lobe); mathematical calculations

- motor --- sequencing movements; performing movements and gestures to command

- emotions --- expressing positive emotions

Front 162

What are the functions of the right hemisphere of the brain?

Back 162

verbal/artistic side

- cognitive style --- processing information in a simultaneous, holistic, or gestalt manner; grasping overall organization or pattern

- perception/cognition --- processing nonverbal stimuli (environmental sounds, speech intonation, complex shapes and designs); visual-spatial perception; drawing inferences, synthesizing information

- academic skills --- mathematical reasoning and judgment; alignment of numerals in calculations

- motor --- sustaining a movement or posture

- emotions --- expressing negative emotions; perceiving emotions

Front 163

Common impairments seen in patients with left hemispheric injury include:

Back 163

- inability to plan motor tasks (apraxia)
- difficulty initiating, sequencing, and processing tasks
- difficulty producing or comprehending speech
- perseveration of speech or motor behaviors
- anxiousness

Front 164

Common impairments seen in patients with right hemispheric injury include:

Back 164

- poor judgment
- unrealistic expectations
- denial of disability or deficits
- disturbances in body image
- irritability
- lethargy

Front 165

Describe the structure and function of the internal capsule.

Back 165

- an area of white matter in the brain that contains both ascending and descending axons (sort of looks like the stalk of a cauliflower floret)

- consists of axonal fibers that run between the cerebral cortex and the pyramids of the medulla

Front 166

What sequelae can a lesion within the internal capsule cause?

Back 166

contralateral loss of voluntary movement and conscious somatosensation

Front 167

What structures comprise the diencephalon?

Back 167

- thalamus
- hypothalamus

(the lecture notes include epithalamus and subthalamus as well)

Front 168

What is the function of the thalamus?

Back 168

- central relay station

- channels sensory impulses (except smell) traveling upward from the rest of the body to the proper areas of the cerebral cortex for processing, including to association areas

- channels motor information from the basal ganglia and cerebellum to the correct motor region

Front 169

What is the function of the hypothalamus?

Back 169

- regulation of homeostasis via regulation of automatic functions (e.g., thirst, hunger, digestion, body temperature, blood pressure, sexual activity, and sleep-wake cycles

- integrates functions of the endocrine system and the autonomic nervous system through regulation of the pituitary gland and its release of hormones

Front 170

What is the function of the hypothalamus?

Back 170

- regulation of homeostasis via regulation of automatic functions (e.g., thirst, hunger, digestion, body temperature, blood pressure, sexual activity, and sleep-wake cycles

- integrates functions of the endocrine system and the autonomic nervous system through regulation of the pituitary gland and its release of hormones

Front 171

What is the function of the basal ganglia?

Back 171

- influence the motor planning areas of the cerebral cortex through various motor circuits

- regulation of posture and muscle tone
- control of volitional and automatic movement
- some cognitive function (caudate nucleus portion)

Front 172

What signs do Parkinson's patients exhibit?

Back 172

- bradykinesia (slowness initiating movement)
- akinesia (difficulty initiating movement)
- tremors
- rigidity
- postural instability

(due to death of cells in the substantia nigra, which produces dopamine)

Front 173

What is the structure and function of the limbic system?

Back 173

- deep brain structures in the diencephalon and cortex that includes parts of the thalamus and hypothalamus and a portion of the frontal and temporal lobes

- controls emotional reactions such as rage and fear (hypothalamus)
- guides emotions that regulate behavior
- learning and memory
- controls memory, pain, pleasure, rage, affection, sexual interest, fear, and sorrow

Front 174

What is the function of the midbrain?

Back 174

- connects diencephalon to the pons

- acts as relay station for tracts passing between cerebrum and spinal cord or cerebellum

- houses reflex centers for visual, auditory, and tactile responses

Front 175

What is the function of the pons?

Back 175

- contains bundles of axons that travel between cerebellum and rest of CNS
- functions with medulla to regulate breathing rate

- contains reflex centers that assist with orientation of head in response to visual and auditory stimulation

- cranial nerve nuclei can also be found within the pons, specifically CN V-VIII for motor and sensory information to/from the face

Front 176

What is the function of the medulla?

Back 176

- extension of the spinal cord containing fiber tracts that run through the spinal cord

- contains motor and sensory nuclei for the neck and mouth regions

- contains control center for heart and respiration rate

- contains reflex centers for vomiting, sneezing, and swallowing

Front 177

What is the function of the reticular activating system?

Back 177

- within the brain stem; extends vertically throughout its length
- maintains and adjusts individual's level of arousal, including sleep-wake cycles

- facilitates voluntary and autonomic motor responses necessary for certain self-regulating, homeostatic functions
- involved in modulation of muscle tone throughout the body

Front 178

Name the two primary ascending sensory tracts present in the white matter of the spinal cord.

Back 178

- dorsal (posterior) columns

- spinothalmic tract

Front 179

What sensory information does the dorsal (posterior) column carry?

Back 179

- proprioception
- vibration
- 2-point discrimination
- deep touch

Front 180

What sensory information does the spinothalmic tract carry?

Back 180

- pain

- temperature sensation

Front 181

Structure and function of the rubrospinal tract

Back 181

- originates in red nucleus of mid-brain
- terminates in anterior horn
- synapses in anterior horn with LMN that primarily innervate the UEs

- fibers facilitate flexor motor neurons, inhibit extensor motor neurons
- proximal muscles primarily affected, but some influence over more distal groups

- thought to assist in the correction of movement errors

Front 182

Function of lateral vestibulospinal tract

Back 182

- assists in postural adjustments through facilitation of proximal extensor muscles

Front 183

Function of medial vestibulospinal tract

Back 183

regulation of muscle tone in the neck and upper back

Front 184

Function of medial reticulospinal tract

Back 184

facilitates limb extensors

Front 185

Function of lateral reticulospinal tract

Back 185

facilitates flexors and inhibits extensor muscle activity

Front 186

Function of the tectospinal tract

Back 186

provides for orientation of the head toward a sound or a moving object

Front 187

What is an anterior horn cell?

Back 187

- large neuron in the gray matter of the spinal cord that sends out axons through ventral spinal roots

- eventually these axons become peripheral nerves and innervate muscle fibers

Front 188

Describe an alpha motor neuron.

Back 188

- type of anterior horn cell that innervates skeletal muscle

- due to axonal branching, one alpha motor neuron can innervate several muscle fibers

- the alpha motor neuron and all the muscle fibers it innervates comprise a motor unit

Front 189

Describe a gamma motor neuron.

Back 189

- type of anterior horn cell

- motor neuron that transmits impulses to intrafusal fibers of the muscle spindle

Front 190

What is a muscle spindle?

Back 190

- sensory organ found in skeletal muscle

- comprised of motor and sensory endings and muscle fibers

- responds to stretch, thus provides feedback to CNS regarding the muscle's length

Front 191

An important fact about stretch or deep tendon reflexes is that their activation and subsequent motor response can occur without....

Back 191

higher cortical influence

(cerebral cortex is not involved in the reflex arc)

Front 192

Why is it clinically important that the cerebral cortex is not involved in the reflex arc?

Back 192

because a patient with a spinal cord injury can still exhibit lower extremity deep tendon reflexes despite lower extremity paralysis

Front 193

Describe the somatic component of the PNS (the SNS).

Back 193

- voluntary, conscious control
- reactions to outside stimulation
- skeletal muscle contraction by way of 31 pairs of spinal nerves
- also 12 pairs of cranial nerves, which are sensory and motor (innervate SCM and trapezius)

Front 194

Describe the autonomic component of the PNS (the ANS).

Back 194

- involuntary
- innervates glands, smooth (visceral) muscle, and cardiac muscle
- primary function is to maintain homeostasis
- regulation of digestion, circulation, and cardiac muscle contraction

Front 195

Where are the cranial nerves located?

Back 195

in the brain stem

(but they are a part of the PNS!!)

Front 196

How are the spinal nerves numbered, and how do they correlate to the vertebrae?

Back 196

- C1 through C7 exit above the same numbered vertebra

- C8 exits above T1 (or below C7)

- thereafter, the nerves exit below the vertebra (e.g., L3 spinal nerve exits below L3 vertebra)

Front 197

Once through the intervertebral foramina, the spinal nerves...

Back 197

- divide into two primary rami

- this division represents the beginning of the PNS

Front 198

Which spinal nerves form plexuses?

Back 198

the anterior primary rami of the
- cervical (C1-C4)
- brachial (C5-T1)
- lumbosacral (L1-S3)

- no plexuses in the thoracic

Front 199

Describe the cervical plexus.

Back 199

- comprised of anterior primary rami of the C1-C4 spinal nerves

- primarily innervate
---- deep muscles of neck,
---- superficial anterior neck muscles,
---- levator scapulae,
---- portions of the trapezius and SCM

Front 200

Describe the phrenic nerve.

Back 200

- within cervical plexus
- formed from branches of C3-C5
- innervates the diaphragm
- only motor and main sensory nerve for this muscle

Front 201

Describe the brachial plexus.

Back 201

- comprised of anterior primary rami of the C5-T1 spinal nerves

- divides and comes together several times, providing redundant motor and sensory innervation from more than one spinal nerve root level

- 5 primary nerves:
---- musculocutaneous - forearm flexors
---- axillary
---- radial - elbow, wrist, and finger extensors
---- median - forearm pronators, wrist and finger flexors, thumb abductors and opposers
---- ulnar - assists median nerve with wrist and finger flexion, abducts/adducts fingers, opposition of 5th finger

- innervates the majority of the UE musculature, except
---- medial pectoral nerve (C8) - pectoralis muscles
---- subscapular nerve (C5-C6) - subscapularis
---- thoracodorsal nerve (C7) - latissimus dorsi

Front 202

Describe the lumbosacral plexus.

Back 202

- innervate LE musculature
- comprised of the anterior primary rami of the L1-S3 spinal nerves
- does not undergo the same separation and reuniting as does the brachial plexus

- innervates muscles of
---- thigh
---- lower leg
---- foot

- 8 roots that form 6 primary peripheral nerves
---- obturator
---- femoral
---- superior gluteal
---- inferior gluteal
---- common peroneal
---- tibial
(common peroneal and tibial form sciatic nerve)

Front 203

Describe the motor fibers of a peripheral nerve.

Back 203

- large cell body with multiple branched dendrites (multipolar) located within anterior horn of spinal cord

- long axon that exits the anterior horn through the white matter and bundles with other similar axons in the ventral root in the intervertebral foramen

- becomes part of a peripheral nerve and innervates a motor end plate in a muscle

Front 204

Describe the sensory fibers of a peripheral nerve and the routing of a sensory signal.

Back 204

- dendrite originates in the skin, muscle tendon, or golgi tendon organ

- action potential travels from skin/tendon/GTO to cell body in the dorsal root ganglion within the intervertebral foramen for processing

- action potential continues from cell body through axon and into the dorsal root of the spinal nerve

- then passes into the gray matter of the spinal cord through the dorsal horn

- may then synapse with interneuron, relay to motor neuron, and constitute a reflex arc, or decussate to the other side of the gray matter, exit the gray matter, enter the white matter fiber tracts and ascend to a different level in the spinal cord or brain stem

Front 205

Name the functions of the ANS.

Back 205

regulation of
- circulation
- respiration
- digestion
- metabolism
- secretion
- body temperature
- reproduction

Front 206

Where is the control center for the ANS?

Back 206

- hypothalamus
- brain stem

Front 207

The ANS is composed of motor neurons located within spinal nerves that innervate....

Back 207

- smooth muscle
- cardiac muscle
- glands

(a.k.a. effectors or target organs)

Front 208

Divisions of the ANS

Back 208

- sympathetic nervous system

- parasympathetic nervous system

Front 209

Which division of the ANS innervates internal organs, the sympathetic, or parasympathetic?

Back 209

- both

- they affect the organs in basically antagonistic ways

Front 210

Describe the neural pathway of the sympathetic and parasympathetic divisions of the ANS.

Back 210

- two-neuron pathway (presynaptic and postsynaptic)

- one-ganglion impulse conduction between the ganglia

Front 211

How do the sympathetic and parasympathetic nervous systems achieve autoregulation?

Back 211

- by integrating information from peripheral afferents with information from receptors within the CNS

- the two-neuron pathway (preganglionic and postganglionic neurons) provides the connection from the CNS to the autonomic effector organs

- cell bodies of the preganglionic neurons are located within the brain or spinal cord, and the myelinated axons exit the CNS and synapse with postganglionic cell bodies

- unmyelinated axons from postganglionic neurons innervate the effector organs

Front 212

The sympathetic fibers of the ANS arise from which vertebral levels?

Back 212

- thoracic and lumbar

- motor functions of the sympathetic nervous system take one of 5 paths:
---- via paravertebral ganglionic chain to cervical or sacral levels
---- directly to tissue
---- to a thoracic organ
---- to a collateral ganglion enroute to an abdominopelvic organ
---- to adrenal medulla

Front 213

The sympathetic nervous system evokes the "______ or ______" response, while the parasympathetic nervous system evokes the "_______ and ______" response.

Back 213

- fight or flight

- rest and digest

Front 214

Activation of the sympathetic nervous system causes what reaction in the cardiopulmonary system?

Back 214

- vasoconstriction of blood vessels, increasing BP and pulse rate

- blood flow diverted to muscles from GI tract

Front 215

From where does the parasympathetic nervous system receive its information?

Back 215

from the brain stem, specifically cranial nerves:
- III - oculomotor
- VII - facial
- IX - glossopharyngeal
- X - vagus

- and from lower sacral segments of the spinal cord

Front 216

Motor fibers of the vagus nerve innervate:

Back 216

- myocardium
- smooth muscles of lungs
- smooth muscles of digestive tract

Front 217

Parasympathetic nervous system activation of the vagus nerve can cause:

Back 217

- bradycardia
- decreased force of cardiac muscle contraction
- bronchoconstriction
- increased mucus production
- increased peristalsis
- increased glandular secretion

Front 218

Parasympathetic nervous system activation of the lower sacral segments can cause:

Back 218

- emptying of bowels
- emptying of bladder
- arousal of sexual organs

Front 219

Which neurotransmitters are used at the preganglionic synapses for both the sympathetic and parasympathetic nervous systems?

At the sympathetic and parasympathetic postganglionic synapses with effector cells?

Back 219

- both the sympathetic and parasympathetic nervous systems use the neurotransmitter acetylcholine at the preganglionic synapse

- at the postganglionic synapse, the parasympathetic nervous system uses the neurotransmitter acetylcholine, however, the sympathetic nervous system uses norepinephrine (noradrenaline) to fuel "fight or flight"

Front 220

Activation of the parasympathetic nervous system causes what cardiovascular effects?

Back 220

- dilation of arterioles; vasodilation

- decreased heart rate
- lowered blood pressure
- return of normal GI activity

Front 221

How does the CNS exert influence over the ANS?

Back 221

- via hypothalamus which regulates functions such as digestion

- via the medulla, which controls heart and respiration rates

Front 222

Why is it necessary that the neurons of the brain receive a constant supply of blood?

Back 222

- the neurons in the brain are unable to carry out glycolysis or store glycogen

- they need a continuous supply of glucose and oxygen

- the blood is the only way to obtain the fuel the brain needs

Front 223

All arteries to the brain arise from the ______ ____.

Back 223

aortic arch

Front 224

Which cerebral artery is the largest and most often occluded?

Back 224

the middle cerebral artery (which supplies the lateral surface as well as the deep frontal and parietal lobes of the brain with blood)

Front 225

Which vessels comprise the anterior circulation to the brain?

Back 225

- middle cerebral artery
- anterior cerebral artery

Front 226

Posterior circulation to the brain is composed of the two vertebral arteries, which are branches of the _______.

Back 226

subclavian artery

Front 227

The vertebral arteries supply blood to the ______ and ______, and unite to form the ______ ______.

Back 227

- brain stem
- cerebellum

- basilar artery

Front 228

The basilar artery supplies the _____ ____ and the medial portion of the _______ and ________ lobes.

Back 228

- brain stem
- temporal
- occipital

Front 229

What vessels form the Circle of Willis?

Back 229

- anterior cerebral artery (left and right)
- anterior communicating artery

- internal carotid artery (left and right)

- posterior cerebral artery (left and right)
- posterior communicating artery (left and right)

- the basilar artery and middle cerebral arteries which supply the brain are also considered part of the circle

Front 230

What is the benefit of the Circle of Willis?

Back 230

- its design ensures that failure or occlusion of one cerebral artery does not critically decrease blood flow to that region

- the occlusion can be circumvented or bypassed to meet the nutritional and metabolic needs of cerebral tissue

Front 231

What are the aftereffects of arterial obstruction of sufficient duration within the CNS?

Back 231

- cell and tissue death within minutes
- neurons that die due to oxygen deprivation cannot regenerate
- neurons in the vicinity of damage are susceptible to injury secondary to release of glutamate, an excitatory neurotransmitter

Front 232

What are glutamate's effects within the nervous system?

Back 232

- it is an excitatory neurotransmitter

- at normal levels it assists with CNS functions
- at higher levels, however, it can be toxic to neurons and can promote neuronal death

- it also facilitates calcium release, which ultimately produces a cascade of events, including liberation of calcium-dependent digestive enzymes, cellular edema, cell injury, and cell death

Front 233

How long does it take for changes within oxygen-deprived neurons to manifest? What changes occur? What are the sequelae?

Back 233

- no changes evident for 12-24 hours
- by 24-36 hours the damaged area becomes soft and edematous

- liquifaction and cavitation begin, and the area of necrotic tissue is eventually converted into a cyst
- in time, the infarct retracts and the cystic cavity will be surrounded by a glial scar

- the damaged neurons will not be replaced, and the original function of the area will be lost

- nearby undamaged axons demonstrate collateral sprouting 4-5 days after injury
- these sprouts replace the damaged synaptic area, increasing input to other neurons
- although collateral sprouts do not replace original circuits, they do develop from systems most closely associated with the injured area

Front 234

What are the most common causes of PNS nerve injuries?

Back 234

- usually from other than vascular compromise

common causes include:
- stretching
- laceration
- compression
- traction
- disease
- chemical toxicity
- nutritional deficiency

Front 235

How does the response to injury of nerves of the PNS differ from that of nerves of the CNS?

Back 235

- if the cell body is destroyed, regeneration is not possible and wallerian degeneration occurs

- if the damage to the peripheral nerve is not too significant and occurs only to the axon, regeneration is possible

- axonal sprouting from the proximal end of the damaged axon can occur

- to have a return of function, the axon must grow and reinnervate the appropriate muscle; failure to do so results in degeneration of the axonal sprout

Front 236

Describe wallerian degeneration.

Back 236

when the cell body of a PNS nerve is destroyed, regeneration is not possible, but if the axon is severed:
- the axon terminal degenerates
- the axon undergoes necrosis distal to the site of injury
- the myelin sheath begins to pull away, breaks down, and forms debris
- cell body undergoes metabolic changes
- presynaptic terminals retract from dying cell body
- postsynaptic cells degenerate
- the Schwann cells phagoctize the area

Front 237

How fast can a damaged PNS axon regrow?

Back 237

1.0 mm per day, depending on size of the nerve fiber

Front 238

Upon what does the rate of recovery from a peripheral nerve injury depend?

Back 238

- age of patient

- distance between lesion and destination of the regenerating nerve fibers

Front 239

Describe an upper motor neuron injury.

Back 239

- damage to the corticospinal tract between the frontal lobe and the spinal cord

clinical signs include:
- spasticity (increased resistance to passive stretch)
- hyperreflexia
- presence of Babinski sign
- possible clonus (repetitive stretch reflex that is elicited by passive dorsiflexion of the ankle or passive extension of the wrist)

Front 240

Describe a lower motor neuron injury.

Back 240

injury to:
- the anterior horn cell
- motor nerve cells of brain stem
- spinal root
- spinal nerve

clinical findings include:
- flaccidity
- marked muscle atrophy
- muscle fasciculations
- hyporeflexia

Front 241

What are the functions of the other descending motor tracts (extrapyramidal system)? ***

Back 241

- efferent tracts originating from location other than precentral gyrus of cortex (subcortical motor areas,) primarily different areas of the brainstem

- primarily involved with quality of motor function, equilibrium reflexes, spinal reflexes

Front 242

Name two efferent extrapyramidal descending tracts. ***

Back 242

- vestibulospinal

- rubrospinal

Front 243

Describe the vestibulospinal efferent extrapyramidal descending tract. ***

Back 243

vestibular nuclei in brainstem to anterior horn cells to extensor muscles

- destination: anterior horn (alpha and gamma motor neurons)

Front 244

Describe the rubrospinal efferent extrapyramidal descending tract. ***

Back 244

- red nucleus in brainstem to anterior horn cells

- destination: anterior horn (alpha and gamma motor neurons)

Front 245

What is the function of the spinothalamic tract? ***

Back 245

- ascending (afferent/sensory) tract

- transmites pain, temperaure, touch (crudely localized, e.g., "leg"--general area

Front 246

Describe the route of the spinothalamic tract. ***

(Be able to do this from memory for the test!!)

Back 246

- cutaneous receptors to
- dorsal root ganglion, to
- posterior (dorsal) horn, then
- extensive synapses with interneurons (at spinal cord level as well as suprasegmentally--divergence) for possible reflex responses

- information being transmitted to the brain crosses (within 2-3 segments) to contralateral spinal cord and travels cranially as the ventro-lateral spinothalamic tract
- tract (and information) ascends to thalamus, which acts as a relay station, then the signal
- travels on to cerebral cortex

Front 247

What is the result of a lesion to the spinothalamic tract? ****

Back 247

- loss of pain/temperature/crude touch sensation in opposite side of body below the level of the injury

Front 248

Describe the lemniscal system of the dorsal columns. ***

Back 248

includes:
- fasciculus gracilis
- fasciculus cuneatus

transmits:
- conscious proprioception
- discriminative touch, (2 pt discrimination—how many fingers you are being poked with, etc.)
- stereognosis—know what you’re touching, recognize by feeling)
- vibration

- receptors in skin, joints, tendons (GTO), muscles

Route:
- receptors located cutaneously and deep in joint/tendons/muscles
- via dorsal root ganglion
- spinal cord
- travels ipsilaterally entire cord in dorsal columns
- brainstem
- crosses to other side
- postcentral gyrus

Front 249

What is the fasiculus cuneatus? ***

Back 249

lateral dorsal column that receives information from arms

Front 250

What is the fasiculus gracilis? ***

Back 250

medial dorsal column that receives information from legs

Front 251

What is caused by a lesion on the posterior (dorsal) columns? ***

Back 251

- inability to recognize common objects by touch
- loss of vibratory sensation

(on ipsilateral side below level of lesion)

Front 252

What is the function of the spinocerebellar tract? ***

Back 252

unconscious movement and position sensation

Front 253

Where are the receptors for the spinocerebellar tract? ***

Back 253

deep in joints, tendons, muscles

Front 254

Describe the route of the spinocerebellar tract. ***

Back 254

- receptors located deep in joints/tendons/muscles, to
- dorsal root ganglion
- dorsal root,
- posterior horn of spinal cord
- travels ipsilaterally in lateral column
- to ipsilateral cerebellum

Front 255

What functions does the cerebellum carry out upon receiving information via the spinocerebellar tract? ***

Back 255

cerebellum:
- processes input with other incoming information to control:
--- motor activity
--- equilibrium
--- muscle tone at the unconscious (automatic) level

Front 256

What occurs if there is a lesion in the spinocerebellar tract? ***

Back 256

- poorly controlled movments
- poor equilibrium responses
- abnormal postural sway with eyes shut

Front 257

List the major motor tracts. ***

Back 257

pyramidal
- corticospinal tract - main tract for nearly all volitional muscle activity
- corticobulbar tract - how corticospinal tract is referred to in the brain stem with cranial nerves

extrapyramidal
- vestibulospinal tract - brain stem to anterior horn cells to extensor muscles, maintain balance of body and head
- rubrospinal tract - red nucleus in brain stem to anterior horn cells to flexor muscles; large muscle movement and fine motor control (generally upper limb)
(also reticulospinal and olivospinal)

Front 258

List the major sensory tracts. ***

Back 258

- spinothalamic tract - pain, temperature, crudely localized touch
- lemniscal system (dorsal columns--fasciculus cuneatus/arms, fasciculus gracilis/legs, etc) - conscious proprioception, discriminative (2-point) touch, stereognosis, vibration
- spinocerebellar tract - unconsious movement and position sensation

Front 259

What is a reflex? ***

Back 259

- a stereotyped involuntary motor response to well-defined stimulus

- not learned--an inborn neural circuitry

Front 260

What are the three general types of reflexes? ***

Back 260

- spinal reflexes (spinal cord)
- postural reflexes (brainstem)
- equilibrium reflexes (cortical)

Front 261

What is a spinal reflex? ***

Back 261

- reflex occurring at the spinal cord level; does not require supraspinal (cortical) input

- a hardwired response

- requires an intact simple reflex arc:
--- receptor/special sense organ
--- afferent neuron to SC
--- interneuron(s) in SC
--- efferent neuron (AMN) to effector/muscle
(does not travel up the SC)

Front 262

What are the types of spinal reflexes? ***

Back 262

- muscle stretch reflexes - quick stretch sensed by muscle spindles
- flexor withdrawal reflex - flexion of body part away from noxious stimulus
- crossed extensor reflex - compensates for flexor withdrawal with opposite limb (e.g., to ensure we don't fall down)

Front 263

Describe a muscle stretch reflex. ***

Back 263

myostatic or deep tendon reflexes (DTRs) cause knee, ankle, biceps, and triceps jerk

Front 264

How is a muscle stretch reflex elicited? ***

Back 264

1) quick stretch to muscle stimulates special receptors in muscle (muscle spindles)
2) action potentials fired to DRG; posterior horn of spinal cord

3) immediately synapses with motor neurons or interneurons at appropriate segmental level (excitation of agonist muscle; inhibitions of antagonist muscle)
4) resulting in contraction of agonist (muscle which was stretched) and relaxation of antagonist (reciprocal inhibition): antagonist muscle inhibited during activation of agonist muscle)

5) reflex allows for rapid protection of a muscle which is being rapidly stretched
6) common DTRs tested clinically; C5: biceps jerk, C7: triceps jerk, L4; knee jerk, S1: ankle jerk

7) therapeutic considerations: rationale for stretching a muscle slowly and quick stretch to facilitate a muscle contraction

Front 265

Describe the flexor withdrawal reflex. ***

Back 265

1) noxious stimulus to cutaneous receptors (UE)
2) fire action potentials to DRG…posterior horn

3) immediately synapse with interneurons at appropriate segmental levels (excitatory polysynaptic potentials (EPSPs) to flexor muscles)
4) resulting in flexion of body part/s away from noxious stimulus (you pull your hand off a hot burner)

Front 266

Describe the crossed extensor reflex. ***

Back 266

1) noxious stimulus to cutaneous receptors (UE)
2) fire action potentials to DRG…posterior horn….
3) immediately synapse with interneurons (excitation of flexor muscle/same leg and extensor muscle/opposite leg)

Front 267

Explain the neural pathways of the withdrawal and crossed extensor reflexes in the picture. ***

Back 267

- person steps on tack
- sensory information travels to dorsal horn and
---- passes through the gray matter and travels up the spinothalamic tract for processing in the brain
---- synapses with interneuron in gray matter, which synapses with motor neurons at the ventral horn to create a reflex arc to lift foot (withdrawal reflex)
---- travels up to multiple levels (divergence) to further effect withdrawal reflexes and crossed extension reflexes (flexes hip, tenses gluteals and quadriceps to support weight)

Front 268

What may override spinal reflexes, and when does it happen? ***

Back 268

- higher cortical function may override spinal reflexes

(e.g., you manage to hang onto a hot cup of coffee for the few seconds it takes to set it down without spilling it)

Front 269

What happens when spinal reflexes are disrupted by SCI or PNI? ***

Back 269

- below SCI, spinal reflexes are exaggerated (hyperreflexia) because the reflex arc connections have been interrupted

- at level of PNI, spinal reflexes are lost (hyporeflexia) because the reflex arc connections have been interrupted

Front 270

How are spinal reflexes graded? ***

0 -
1+ -
2+ -
3+ to 4+ -

Back 270

- areflexia
- hyporeflexia
- normal
- hyperreflexia

Front 271

Describe a lower motor neuron. ***

Back 271

- final common pathway from anterior horn outward

-anterior horn cell (alpha/gamma motor neuron) and axon which transmit efferent info to ventral root of spinal nerve to peripheral nerve to synapse at motor end plate

- “final common pathway” of neuronal impulses from CNS to muscle; primarily corticospinal tract

Front 272

What are the results of a LMN lesion? ***

Back 272

- loss of motor commands from motor neuron in spinal cord and
- loss of reflex activity; reflex arc interrupted

Characteristics:
1. hypotonicity – decreased resistance to passive stretch; flaccidity
2. hyporeflexia – diminished/absent spinal reflex arc mechanism
3. paralysis/paresis (very weak) – impaired volitional movement
4. rapid and significant mm atrophy/wasting
5. fasiculations and/or fibrillation – palpable/non-palpable twitches of muscle fibers in denervated tracts (circular)

Front 273

Describe an UMN. ***

Back 273

motor neuron in cortical region and axon which transmit efferent information to spinal cord/anterior horn cell (motor neuron)

Front 274

What results from an UMN lesion? ***

Back 274

- loss of motor commands from CNS and
- inhibition of spinal reflexes by higher brain centers

1. hypertonicity – increased resistance to passive stretch; spasticity/rigidity/clonus
2. hyperreflexia – increased reflex activity response to stimulus
3. paralysis/paresis – loss of volitional movement
4. minimal muscle atrophy secondary to disuse

Front 275

Describe a complete SC transection. ***

Back 275

- complete severance of spinal cord
- common with traumatic spinal cord injuries (MVA, diving, etc.)
- can occur at cervical, thoracic, lumbar regions

- complete loss of sensory and motor function below level of lesions
- hypertonicity, hyperreflexia

Front 276

True or false:
If a patient exhibits hyporeflexia they most likely have a peripheral nerve injury rather than a spinal nerve injury. ***

Back 276

true

Front 277

True or false:
The flexor withdrawal reflex is when the extremity opposite the one that received the stimulus extends. ***

Back 277

false
this is the crossed extensor reflex

Front 278

True or false:
A grade of 2+ indicates normal reflex activity. ***

Back 278

true

Front 279

True or false:
A patient with an upper motor neuron lesion can be expected to exhibit hypertonicity. ***

Back 279

true

Front 280

True or false:
A person with a complete cord transection will experience loss of motor and sensory function below the level of the injury. ***

Back 280

true

Front 281

Describe a central cord lesion of the spinal cord. ***

Back 281

- damage to central aspect of spinal cord and sparing of peripheral portions
- common with cervical injuries and resultant hemorrhage/nervous tissue necrosis in cervical region

- pictured lesion interrupts fibers crossing to enter spinothalamic tracts and fibers mediating the tendon stretch reflex; if this lesion enlarges, it will also affect the intermediolateral columns (ANS functions) and lateral corticospinal tracts
- sensorimotor impairment of upper extremities, greater in lower extremities because of spatial orientation of fiber tracts (cervical segments are located closer to central gray matter)
- possible hypertonia, hyperreflexia

- depends on how much of cord is involved

Front 282

Describe a hemisection spinal cord lesion. ***

Back 282

- damage to one-half (R or L/ant or post) of spinal cord
- common with bullet/stab wounds, spinal cord tumors

Front 283

What is the resultant sensorimotor impairment from Brown-Sequard syndrome? ***

Back 283

- sensorimotor impairment below level of lesion as follows:
1. ipsilateral loss of motor function
2. ipsilateral loss of proprioception,
3. contralateral loss of pain, temperature
- possible hypertonicity, hyperreflexia

Front 284

What is the result of a posterior cord lesion? ***

Back 284

- damage to dorsal columns
- loss of proprioception sensation from extremities resulting in ataxia (incoordination – can’t sense where extremity is)
- also loss of discriminative touch, steriognosis, sensation of vibration
- sparing of motor function, pain, temperature

- common with tabes dorsalis (tertiary syphilis) AIDS patients, traumatic SCI/tumors (depending on site of lesion)

Front 285

What is the result of an anterior cord lesion? ***

Back 285

- damage to ventral aspect of spinal cord
- due to incomplete spinal cord trauma, tumor

- loss of motor function, pain, temperature below level of lesion
- sparing of proprioception below level of lesion
- possible hypertonicity, hyperreflexia

Front 286

What is spina bifida? ***

Back 286

- failure of neural tube closure in utero, associated with maldevelopment of vertebrae
- meninges of spinal cord balloon out into a sac overlying the deformed vertebrae

- not a significant problem unless spinal cord herniates into sac (meningomyelocele) resulting in severe sensorimotor impairments below level of lesion
- possible hypertonicity, hyperreflexia

Front 287

What is Amyotrophic Lateral Sclerosis? ***

Back 287

(ALS – Lou Gehrig’s Disease)

progressive disease of corticospinal tracts with initial paralysis of UE then LE muscles and progressing to respiratory muscles

Front 288

What is an HNP and what are its potential effects? ***

Back 288

Herniated Nucleus Pulposus

- results in pressure on ventral and/or dorsal nerve roots;
- pain/paresthesias in dermatomal distribution for that spinal nerve;
- muscle paresis in myotomal distribution

Front 289

What is poliomyelitis and what are its effects? ***

Back 289

- destruction of anterior horn cells due to acute infection

- results in flaccid paralysis, hyporeflexia
- affects LMN

Front 290

Match the descriptions with the following pathologies: ***

1. destruction of anterior horn cells
2. loss of motor function, pain, temperature below lesion
3. sensorimotor impairment of UE and LE
4. loss of motor function ipsilateral below lesion

a. anterior cord lesion
b. central cord lesion
c. hemisection cord lesion
d. poliomyelitis

Back 290

- d
- a
- b
- c

Front 291

Describe the structure and function of the brainstem. ***

Back 291

- most caudal part of brain, lower end joins spinal cord through foramen magnum
- consists of a central ventricle (4th) surrounded by a core of gray matter, surrounded by white matter (sensory and motor tracts) with various nuclei interspersed
- location centrally for the fourth ventricle which contains cerebrospinal fluid which flows to and from spinal cord

- many features in common with spinal cord
- contains descending and ascending tracts to and from spinal cord (all afferent and efferent tracts pass through here)

- also has features which distinguish it as part of the brain (distinct nuclei)
- compact, diverse functions as relay station for all information moving between spinal cord, cerebellum, and cerebrum

- provides face and neck with sensory and motor innervation via multiple cranial nerves
- provides pathways to and from cerebellum, cerebellar peduncles; stalks of axonal fibers which communicate between cerebellum and cortical/sc regions
- provides control over certain visceral functions (respiratory rate, heart rate, blood pressure, gi functions) via cranial nerves
- provides control over cerebral arousal level (level of consciousness) via reticular formation

- contains various nuclei other than cranial nerves, among them:
--- vestibular nuclei: which feed info from vestibular system to vestibulospinal tract
--- red nucleus: which feeds info from cerebellum to rubrospinal tract

Front 292

What are the three divisions of the brainstem (superior to inferior)? ***

Back 292

- midbrain
- pons
- medulla oblongata

Front 293

All divisions of the brainstem contain: ***

Back 293

- ascending/descending tracts
- different cranial nerve nuclei
- cerebellar peduncles
- portions of reticular formation

Front 294

Describe the medulla oblongata. ***

Back 294

- most inferior aspect of brainstem
- direct communication to SC

- contains decussation of pyramids, decussation of dorsal column tracts
- cardiovascular and respiratory reflex centers

Front 295

Cranial nerve locations ***

Back 295

(see picture)

Front 296

Describe the pons. ***

Back 296

- superior to medulla
- contains vestibular nuclei (vestibulospinal tracts)

Front 297

Describe the midbrain. ***

Back 297

- extends from pons region to thalamus, smallest region of brainstem

- contains red nucleus cell bodies feeding rubrospinal tract

- periaqueductal gray (gray matter containing endorphin producing cells which suppress pain)

Front 298

Describe the cranial nerves. ***

Back 298

- 12 pairs, exit/enter in or near brainstem level

- 9 emerge solely from brainstem;
---- CN I and II are not true nerves but fiber tracts from the brain,
---- CN XI is derived in part from upper cervical spinal nerves

- some cranial nerves purely sensory, some are purely motor, some are both
- some innervate visceral components, some somatic

Front 299

Clinical signs with involvement of CN nuclei (ipsilateral): ***

CN III

Back 299

absence of pupil constriction

Front 300

Clinical signs with involvement of CN nuclei (ipsilateral): ***

CN III, IV, VI

Back 300

- strabismus
- diplopia
- ptosis

Front 301

Clinical signs with involvement of CN nuclei (ipsilateral): ***

CN V

Back 301

- facial anesthesia/pain
- mouth/gums (pain?)
- difficulty chewing

- Tic Doloureaux - excruciating pain in CN V distribution

Front 302

Clinical signs with involvement of CN nuclei (ipsilateral): ***

CN VII

Back 302

- dry eye
- dry mouth
- paralysis of facial muscles of expression
- inability to close eyelid

- Bell's Palsy - facial paralysis

Front 303

Clinical signs with involvement of CN nuclei (ipsilateral): ***

CN VIII

Back 303

cochlear nucleus
- tinnitus
- deafness

vestibular nucleus
- vertigo
- vomiting
- nystagmus

Front 304

Clinical signs with involvement of CN nuclei (ipsilateral): ***

CN IX and X

Back 304

- difficulty swallowing
- dysphonia
- hoarseness

Front 305

Clinical signs with involvement of CN nuclei (ipsilateral): ***

CN XI

Back 305

- weakened shoulder shrug and head turning

Front 306

Clinical signs with involvement of CN nuclei (ipsilateral): ***

CN XII

Back 306

- paralysis of side of tongue with deviation of protruded tongue to that side

Front 307

Clinical signs with impairment of ascending/descending tracts (contralateral.) ***

Back 307

- primarily impairment of corticobulbar/spinal tract
- contralateral hemiplegia/sensory loss

- "Locked-in syndrome": occlusion of vascular supply to pyramidal tract, results in loss of motor/speech; reticular formation intact; alert and aware but only possible movement is slight eye movement
(Diving Bell and the Butterfly)

Front 308

Describe the reticular formation. ***

Back 308

- reticular nuclei and tracts
- dotted lines indicate the extent of the reticular formation

- reticular nuclei include the ventral tegmental area, pedunculopontine nucleus, locus ceruleus, and raphe nuclei
- two of the upper motor neuron tracts that arise in the reticular formation, the reticulospinal tracts, are shown
- the ceruleospinal and raphespinal tracts also arise in the reticular formation (not illustrated).

Front 309

Clinical signs with impairment of reticular formation. ***

Back 309

- decreased level of consciousness
- coma

Front 310

Describe the cerebellum. ***

Back 310

- second largest part of brain
- consists of two lateral hemispheres which communicate with rest of CNS via cerebellar peduncles

- has cortex (gray matter), deep white matter, deep nuclei
- does not initiate motor activity but regulates/modifies motor activities

Front 311

What are the cerebellar peduncles? ***

Back 311

fibers connecting cerebellum to brainstem

Front 312

Function of the cerebellum ***

Back 312

- receives sensory input from many areas (primarily vestibular system, proprioceptors in muscles/spinocerebellar tract)
- not a part of conscious sensory awareness, deals with unconscious sensory

control center for:
- coordination of voluntary muscle activity
- equilibrium and balance
- muscle tone
- some evidence of involvement in memory

relays modification information to PNS indirectly through numerous circuits in brainstem/cerebrum, corticospinal tract

cerebellar input :
- proprioceptive info from muscles regarding speed and position and tone (muscle spindles, GTO)
- equilibrium info from vestibular system (elicits postural adjustments in response to head tilt)
- motor commands from cerebral cortex

Front 313

Clinical signs of cerebellar lesions ***

Back 313

- unilateral lesions lead to motor disabilities ipsilateral to the side of the lesion

- usually have bilateral cerebellar damage with bilateral involvement
- lesions do not cause paralysis but result in uncoordinated, poor quality movement and overall low tonus

- hypotonia
- ataxia
- nystagmus
- dysmetria
- intention tremor
- postural tremor
- rebound phenomenon
- dysdiadochokinesia
- dysarthria
- disorders of gait

Front 314

What is hypotonia? ***

Back 314

- sign of a cerebral lesion

-decreased muscle tone
- muscles feel soft and flabby

Front 315

What is ataxia? ***

Back 315

- sign of a cerebral lesion

- loss of coordinated muscular contractions required for production of smooth movements
- jerky, irregular movements instead of smooth continuous movements

- inconsistent speed of movement (affects posture, gait, limb movements)

- feedback loops not working properly

Front 316

What is nystagmus? ***

Back 316

- sign of a cerebral lesion

- rhythmic oscillation of eyeballs

Front 317

What is dysmetria? ***

Back 317

- sign of a cerebral lesion

- impaired ability to judge distance or range of movement (overshooting or undershooting a target, e.g, when trying to grab an object)

Front 318

What is intention tremor? ***

Back 318

- sign of a cerebral lesion

- tremors of extremity during movement that disappear at rest

Front 319

What is dysdiadochokinesia? ***

Back 319

- sign of a cerebral lesion

- impaired ability to perform rapidly alternating movements (e.g., walking)

Front 320

What is rebound phenomenon? ***

Back 320

- sign of a cerebral lesion

- loss of normal checks of agonist and antagonist muscles

Front 321

What is postural tremor? ***

Back 321

- sign of a cerebral lesion

- back and forth oscillatory movements of body in static posture

Front 322

What is dysarthria? ***

Back 322

- sign of a cerebral lesion

- slow, slurred speech

Front 323

What disorders of gait are noted in conjunction with cerebellar lesions? ***

Back 323

- broad base of support
- arms held out away from body to improve balance
- inconsistent speed of gait
- irregular gait pattern with deviation from forward line of progression (staggering)

Front 324

What is the diencephalon? ***

Back 324

- mass of gray matter (numerous large nuclei)
- superior to brainstem and deep in cerebrum
- contains 3rd ventricle which lies between the halves of the diencephalon

Front 325

Name the divisions of the diencephalon. ***

Back 325

- thalamus
- hypothalamus
- subthalamus
- epithalamus

Front 326

Describe the structure and function of the thalamus. ***

Back 326

- largest gray matter structure in diencephalon; contains clusters of nuclei
- involved with movement, sensation, emotion, and memory information

- major relay station for ascending pathways (mainly afferent)
- most sensory nerve tracts from spinal cord and brainstem synapse in thalamus

- thalamic neuron axons project to cerebral cortex (somatotopic representation) (large % to parietal lobe)

Front 327

Most sensory nerve tracts from the spinal cord and brainstem synapse in the _______. ***

Back 327

thalamus

Front 328

Which is the largest gray matter structure in the diencephalon? ***

Back 328

thalamus

Front 329

With what functions is the thalamus involved? ***

Back 329

- movement
- sensation
- emotion
- memory information

Front 330

How is sensory information perceived in the thalamus? ***

Back 330

- interprets sensory information, especially pain/noxious sensation
- sensation is perceived by brain at this region but location is not interpreted until it reaches cortex (you can feel but you cannot locate the area)

(of course it also depends on the wiring of the individual for the definition of “noxious”)

- also connects with basal ganglia (deep within the cerebral hemispheres), cerebellum, and limbic system)

Front 331

Describe the structure and general function of the hypothalamus. ***

Back 331

- group of nuclei inferior to thalamus

- responsible for important regulatory functions of body’ systems; maintenance of homeostasis

Front 332

For what functions is the hypothalamus the control center? ***

Back 332

- appetite
- autonomic function (activation of ANS/visceral functions)
- body temperature (activates responses resulting in loss, conservation, or production of body heat)

- circadian rhythm: (24 hr cycle of body functions: temperature, O2 consumption, corticosteroid levels cyclically influenced by light intensity)
- expression of emotions (rage, fear, aversion, sexual behavior, pleasure)

- growth, reproduction, sexual functions (via regulation of endocrine system)
- water balance (fluid retention/excretion)

Front 333

Describe the structure and function of the subthalamus. ***

Back 333

- nucleus located near the thalamus
- part of the basal ganglia system

- plays a part in modifying motor responses

Front 334

Describe the structure and function of the epithalamus. ***

Back 334

- uppermost portion of diencephalon

- consists of various structures including pineal gland (which influences body’s response to light)

Front 335

List two effects of lesions to the diencephalon. ***

Back 335

- thalamic pain syndrome
- hemiballismus

Front 336

Describe thalamic pain syndrome. ***

Back 336

- vascular damage to thalamus (certain CVAs) result in distortion of all sensory input from contralateral side of the body

- usually accompanied by contralateral paralysis/paresis due to CVA damage to cerebrospinal tract

- patient develops exaggerated responses of burning, agonizing pain in all affected body parts with any type of sensory stimulation to affected areas

Front 337

Describe hemiballismus. ***

Back 337

- lesion to subthalamic nucleus

- involuntary, sudden wild flailing motions of contralateral side of the body

Front 338

Describe the structure of the basal ganglia. ***

Back 338

- consists of several large nuclei located deep within cerebral hemispheres between thalamus and cerebral cortex of each hemisphere

- contains internal capsule: projection that allows fibers to communicate between basal ganglia and other motor areas in the brain

- misnomer: these masses are nuclei not “ganglia” and some are not basal
- part of “extrapyramidal system” (motor regions other than corticospinal tract which is referred to as “pyramidal system”)

divisions:
- caudate nucleus
- putamen
- globus pallidus
- subthalamus

Front 339

What are the functions of the basal ganglia? ***

Back 339

collaborates with all motor areas of brain (cerebral cortex, cerebellum, brainstem, diencephalon) for:
- planning, programming, modification of motor commands (activities)
- subconscious control system for automatic motor activities such as coordinated movements and postural adjustments

Front 340

What are some clinical signs of basal ganglionic lesions? ***

Back 340

malfunction may result in movement disorders (dyskinesia – abnormal movement)
(either too much movement or too little movement, depending on area effected)

clinical signs of lesions:
- akinesia - inability to initiate movement
- rigidity – hypertonicity
- resting tremor – rhythmic oscillatory movements at rest

- chorea – involuntary rapid jerky movement
- tics – spasmodic jerking of muscles, usually facial/neck
- athetosis – involuntary writhing, twisting mvts.
- hemiballismus – involuntary sudden, wild flailing motions of one side of the body

Front 341

Name two examples of basal ganglia disorders. ***

Back 341

- Parkinson's Disease

- Tourette's Syndrome

Front 342

Describe the general function of the cerebrum. ***

Back 342

- largest, most prominent part of brain
- dominates all other aspects of nervous system

- interprets all sensory information
- initiates all volitional motor activities
- serves as the center of intellect, memory, language, behavior

Front 343

Describe the landmarks of the cerebrum. ***

Back 343

external landmarks of cerebrum:

- sulcus: depression or groove
--- central sulcus – located middle of hemisphere (medial to lateral/coronal) separates frontal from parietal lobe
- fissure: deep groove
--- lateral fissure – separates temporal lobe from parietal and frontal lobes

- gyrus: convolutions or folds of cerebrum; lie between two sulci
--- precentral gyrus – located anterior to central sulcus; frontal lobe
--- postcentral gyrus – located posterior to central sulcus; parietal lobe

Front 344

What are the general functions of each hemisphere of the cerebrum? ***

Back 344

- each controls the contralateral side of the body for the majority of sensory and motor functions
- each has four lobes: 1. frontal 2. parietal 3. temporal 4.occipital

--- frontal: primary motor cortex, premotor area, prefrontal area
--- parietal: primary somatosensory cortex (pinch is on the arm), sensory association area
--- temporal: primary auditory cortex, auditory association area
--- occipital: primary visual cortex, visual association area

Front 345

Describe the structure of the hemispheres of the cerebrum. ***

Back 345

- each has an outer layer of gray matter; cerebral cortex (composed of motor—mostly frontal and sensory cell bodies—mostly parietal/interneuronal cell bodies)

- each contains neuronal fibers deep to cortex (subcortical white matter), necessary for processing/integrating sensorimotor information and higher level mental/motor function

- each hemisphere contains deeper gray matter (nuclei) structures:
(e.g., basal ganglia, thalamus, hypothalamus, epithalamus, subthalamus)

- each hemisphere contains a lateral ventricle

Front 346

Name and describe the fibers associated with the cerebrum. ***

Back 346

- association fibers (axons): interconnect neurons within the lobes (long and short)

- commissure fibers: interconnect neurons between the two hemispheres, largest is the corpus collosum which represents the main communication link between right and left hemispheres, most information is transferred between hemispheres at this site

- projection fibers: ascending/descending neuronal fibers within brain and spinal cord

- cingulum

Front 347

Name the largest structure of commissure fibers within the cerebrum. ***

Back 347

corpus collosum

Front 348

Describe the function of the frontal lobe. ***

Back 348

primary motor cortex
- motor control
- beginning of final common pathway for voluntary motor function
- somatotopic (body map) representation of body regions (homunculus)
--- allocates 2/3 cortex for fine motor functions (hands, face, tongue)
--- allocates 1/3 for gross motor functions (trunk, UE, LE, feet)

Front 349

Describe the structure and function of the premotor area of the frontal lobe. ***

Back 349

- complex motor function

- connected neuronally to primary motor cortex via association fibers, work together to perform coordinated/simultaneous/complex movements
(e.g., throwing ball, driving car while changing radio station, or talking while cooking)

- contains Broca’s area (motor for lips and tongue, important for speech)

Front 350

Describe the structure and function of the prefrontal area of the frontal lobe. ***

Back 350

- connects with all other lobes of hemispheres

- abstract thinking, planning, judgment, personality, intellect

- forms part of limbic system (self-control, emotion, social behavior) – affected by all other systems

Front 351

Describe the function of the parietal lobe. ***

Back 351

- primary somatosensory cortex (postcentral gyrus)

- terminal point for somatosensory input relayed from thalamus
- receives, interprets, processes sensory input from body

- sensory modalities include pain, temperature, touch, vibration, pressure, position/movement sense (no vision, smell, auditory as those are via cranial nerves)

- localizes the sensation
- representation of body regions (homunculus) allocates 2/3 to face, mouth, hand, and foot

Front 352

What is the sensory association area? ***

Back 352

an area posterior to postcentral gyrus that:
- integrates all sensory information from primary somatosensory cortex
- responsible for higher order of sensory discrimination (stereognosis—know by feel, two point discrimination, graphesthesia—recognize writing on skin)
- also receives and integrates sensory information from other lobes (visual, taste, and language, both spoken and written)

Front 353

What functions are performed in the temporal lobe? ***

Back 353

primary auditory cortex
- inside lateral fissure
- receives neuronal input from both inner ears
- sound is “realized” here but not comprehended

auditory association area (surrounds primary auditory cortex)
- interprets and integrates auditory information with all other incoming sensory information for appropriate response
- contains Wernicke’s area (interprets sounds as words)

- long-term memory storage

- forms part of limbic system (involved with emotion, behavior)

Front 354

What functions are performed in the occipital lobe? ***

Back 354

primary visual cortex (medial surface of occipital lobe)
- receives visual information via optic nerve

visual association area
- interprets and integrates visual information with all other incoming sensory information (where object is and what object is) for appropriate response

Front 355

What is the sensory homunculus? Where is it represented? ***

Back 355

cortical homunculus is a somatotopic representation of the body parts on the pre/post-central gyri

sensory homunculus
- area on postcentral gyrus (primary somatosensory cortex) which localizes sensory input from a specific area from contralateral body
- each point on the skin/body projects sensory information via a single axonal path to a single point on primary somatosensory cortex
- face, mouth, hand, foot occupy approximately 2/3 of sensory homunculus (lots of sensory input from this area) = SURVIVAL

Front 356

What is the motor homunculus? Where is it represented? ***

Back 356

cortical homunculus is a somatotopic representation of the body parts on the pre/post-central gyri

motor homunculus
- area on precentral gyrus (primary motor cortex) specific to each region of contralateral body commanding individual muscle actions via single axonal path
- motor commands originate in precentral gyrus, travel in cortico-bulbar/corticospinal tracts to motor nuclei in brainstem/spinal cord
- face, mouth, throat, head occupy approx 2/3 of motor homunculus (lots of motor fibers to areas requiring complex, skilled movement)

Front 357

How does handedness/hand dominance affect cortical function? ***

Back 357

- primary and association sensorimotor areas are present in both hemispheres/all lobes
- both hemispheres receive, process and integrate the same basic information

- evidence shows that functional asymmetries exist concerning left and right hemisphere methods of processing this information

- beginning early in life, one hemisphere of the brain develops more intensively than the other for language and speech function
- this is often referred to as the “dominant” hemisphere

- dominant hemisphere is concerned particularly with analytical functions; speech, language, literacy, “reading” music, analytical mathematics
- “non-dominant” hemisphere plays a greater role with interpretation of 3-dimensional images and spatial relationships; design, drawing, music appreciation, dance, person space/body awareness, theoretical mathematics

Front 358

With which cortical functions is the dominant hemisphere concerned? ***

Back 358

- dominant hemisphere is concerned particularly with analytical functions; speech, language, literacy, “reading” music, analytical mathematics

Front 359

With which cortical functions is the non-dominant hemisphere concerned? ***

Back 359

- “non-dominant” hemisphere plays a greater role with interpretation of 3-dimensiaonal images and spatial relationships; design, drawing, music appreciation, dance, person space/body awareness, theoretical mathematics

Front 360

Which hemisphere is dominant in the majority of the population? ***

Back 360

in the majority of population (90-95%), the
- left hemisphere is the dominant hemisphere (language, analytical tasks) and the
- right hemisphere is the non-dominant, hemisphere (spatial appreciation)

Front 361

What types of lesions can affect the primary motor cortex and somatosensory cortex and their associated structures? ***

Back 361

- edema
- infection/disease
- congenital defects
- vascular damage secondary to trauma
- strokes
- vessel malformations

Front 362

How do lesions of the primary motor cortex affect function? ***

Back 362

contralaterally: the area affected depends on somatotopic location
- muscle paresis (weakness) or paralysis (absence)
- spasticity (usually, but may be flaccid)
- hyperreflexia

Front 363

How do lesions of the primary somatosensory cortex affect function? ***

Back 363

contralaterally: the area affected depends on somatotopic location
- paresthesias (numbness, tingling, electric shock)
- impaired ability to distinguish or localize stimuli
- impaired ability to measure intensity of stimulus

Front 364

How do lesions in the motor/sensory association areas affect function? ***

Back 364

- motor association areas: movement will occur but will be uncoordinated, disorganized

- sensory association areas: sensations will be realized but will not be correctly interpreted/processed

Front 365

How do lesions in the prefrontal lobe affect function? ***

Back 365

prefrontal lobe: behavioral impairments, personality changes, impaired judgment, social disinhibitions, poorly controlled behavior

Front 366

Describe the structure and function of the meninges. ***

Back 366

- meninges cover the brain and are continuous with the spinal cord

functions:
- support brain within the skull
- protect the brain
- helps maintain a constant environment in and around brain

Front 367

Name the three meningeal layers. ***

Back 367

- dura mater
- arachnoid mater
- pia mater

Front 368

Describe the dura mater. ***

Back 368

- tough, fibrous outermost membrane

- consists of two layers
--- outer layer firmly attached to cranial bone
--- inner layer continuous with spinal dura

- layers generally fused except in areas where it separates to form venous sinuses (small cavities which collect venous drainage)

- form septa (divisions) separating and containing brain portions
--- falx cerebri - separates 2 hemispheres
--- tentorium cerebelli - separates occipital lobes from cerebellum

- subdural space between dura mater/arachnoid (potential space, normally contains only a few drops of CSF; bleeding into area with vascular trauma = subdural hematoma)

Front 369

Name the septa of the dura mater. ***

Back 369

- septa (divisions) separating and containing brain portions
--- falx cerebri - separates 2 hemispheres
--- tentorium cerebelli - separates occipital lobes from cerebellum

Front 370

Describe the arachnoid mater. ***

Back 370

- middle layer; delicate
- avascular
- weblike

- subarachnoid space between arachnoid mater/pia mater contains CSF and arteries

Front 371

Describe the pia mater. ***

Back 371

- innermost layer
- very thin
- completely invests brain

- combines with other tissue/vascular structures in the ventricle regions to form the choroid plexus (layer that produces CSF)

Front 372

What does the choroid plexus do? ***

Back 372

produces CSF

Front 373

What effects can meningeal lesions have? ***

Back 373

- brain herniations: separation of a septa can result in movement of brain tissue into another area

- herniated tissue can put pressure on other areas of brain
--- can be life threatening if brainstem is compressed (regulatory centers for respiration, consciousness, blood pressure, heart rate)

Front 374

Describe the structure of the ventricular system. ***

Back 374

- communicating system of 5 cavities deep within the brain

four ventricles:
--- 2 lateral ventricles; largest (one deep inside each cerebral hemisphere)
--- third ventricle (separates diencephalon)
--- fourth ventricle (within brainstem)

- interventricular foramen connects lateral/third ventricles
- cerebral aqueduct connects third and fourth ventricles

Front 375

What is CSF? ***

Back 375

cerebrospinal fluid

- clear, colorless, odorless fluid containing nutrients (glucose, proteins)
- produced by the choroid plexus (vascular process of the pia mater)

- choroid plexus components present in all ventricles except cerebral aqueduct (similar to an epithelial layer, but not epithelial)

- CSF is found in ventricular system and subarachnoid space surrounding BS and SC

Front 376

What is the purpose of CSF? ***

Back 376

- provides cushioning support of brain and spinal cord (CNS “floats” in CSF)
- delivers nutrients; transports wastes

- controls CNS excitability by regulating ionic composition
- provides some protection from pressure changes (venous volume vs. CSF volume)

Front 377

Describe the route of CSF circulation? ***

Back 377

- most is formed in lateral ventricles (choroid plexus);
- passes into third ventricle
- then through cerebral aqueduct into fourth ventricle

- through three small foramina into subarachnoid space; and
- circulates around entire surface areas of brain/spinal cord in subarachnoid space

- there is continuous circulation of CSF in and around brain and spinal cord

- CSF is reabsorbed by superior sagittal sinus (venous blood flow in superior aspect of brain) and returned to bloodstream

Front 378

What is hydrocephalus? ***

Back 378

- dilation of ventricles secondary to an abnormal accumulation of CSF

caused by:

- blockage of CSF flow (obstruction, malformation); referred to as non-communicating/obstructive hydrocephalus

- overproduction of CSF and/or inadequate reabsorption of CSF (obstruction of resorption sites); referred to as communicating hydrocephalus (more CSF is being produced than is reabsorbed)

Front 379

What is the difference between non-communicating/obstructive hydrocephalus and communicating hydrocephalus? ***

Back 379

- non-communicating/obstructive hydrocephalus is due to a blockage

- communicating hydrocephalus is due to overproduction of fluid

Front 380

What are the sequelae from and treatment for hydrocephalus? ***

Back 380

- results in increased intracranial pressure (ICP)
- if untreated
--- brain damage resulting in mental retardation
--- neurological deficits
--- cranial deformity (if under 2 years of age)
--- possible death

- shunt: Rx for hydrocephalus
- surgical implantation of catheter in ventricles with drain line which passes from ventricle to either right atria (ventriculoatrial shunt) or to right peritoneal cavity (ventriculoperitoneal shunt)

- control valve on catheter (in ventricle) regulates flow rate
- excess CSF is shunted to other body cavity

Front 381

How is hydrocephalus diagnosed? ***

Back 381

lumbar puncture (spinal tap)
- insertion of special spinal needle into subarachnoid space below the spinal cord level (L3, 4, 5 vertebral level)

Front 382

What are some indications that may be diagnosed via spinal tap? Other uses for spinal taps? ***

Back 382

- measure CSF pressure--increased pressure may be due to:
--- increased CNS volume = tumor
--- increased blood volume = hemorrhage
--- icreased CSF volume = hydrocephalus

- examine CSF for infections
- administer anesthesia

Front 383

CNS cells and tissue require a continuous supply of ______ and _____ for normal functioning. ***

Back 383

- glucose

- oxygen

Front 384

Although the brain is only 2% of the total body weight, it uses _____ of cardiac output and ____ of oxygen absorbed by lungs. ***

Back 384

- 18-20%

- 20%

Front 385

If blood supply to CNS is restricted, how quickly can damage occur? ***

Back 385

- loss of consciousness within 1 minute

- irreversible cell damage within 5 minutes (because once a CNS neuron is dead, it's dead--no regeneration)

Front 386

Describe the distribution patterns of the large cerebral arteries. ***

Back 386

- green area: anterior cerebral artery
- pink area: middle cerebral artery
- yellow area: posterior cerebral artery

Front 387

How does blood flow from the heart to the brain? ***

Back 387

- all arteries to brain arise from aortic arch

common carotids supply bulk of circulation to cerebrum
- bifurcate posterior angle of the jaw to internal and external carotids
--- external supplies face
--- internal supplies cranium and cerebral hemispheres, optic nerves, and retina
----- internal bifurcates into R and L anterior and middle cerebral arteries (together form anterior circulation to brain)

Front 388

Which cerebral artery is the largest and most often occluded? ***

Back 388

middle cerebral artery

(common carotid artery bifurcates at posterior angle of jaw into external and internal carotids;
internal bifucates into R and L anterior and middle cerebral arteries)

Front 389

Describe the blood supply to brain stem and cerebellum. ***

Back 389

- two vertebral arteries are branches of the subclavian arteries
- supply blood to brain stem and cerebellum

- enter skull through foramen magnum
- unite to form basilar (base--) artery

- anterior and posterior communicating arteries are interconnected at base of brain and form Circle of Willis (redundant blood supply)

Front 390

What is the structure and function of the Circle of Willis? ***

Back 390

- provides protection to structures of the brain

- failure or occlusion of one cerebral artery does not critically decrease blood flow to that region

- occlusion can be circumvented or bypassed to meet needs of cerebral tissue

from anterior to posterior, the arteries that form the circle of Willis are:
- anterior communicating
- two anterior cerebral
- two internal carotid
- two posterior communicating, and
- two posterior cerebral arteries.

Front 391

Describe the venous drainange of the brain. ***

Back 391

- cerebral veins differ from systemic veins
--- no valves
--- seldom accompany arteries

- smaller veins located deep in the brain travel to superficial surface of brain
- join larger veins which drain into venous sinuses located in dura mater

(pictured above are the sagittal sinus and transverse sinus)

Front 392

Name the venous sinuses. ***

Back 392

- superior sagittal
- inferior sagittal

- straight
- transverse

Front 393

How do the sinuses route venous return to the superior vena cava? ***

Back 393

sinuses converge at different areas and drain into internal jugular veins which drain into superior vena cava

Front 394

What is the blood-brain barrier? ***

Back 394

- certain structures in close contact with CNS (astrocytes, arterial vessels, arachnoid layer) are specially designed to serve as a protective barrier for the CNS

- these structures are designed with:
--- very tight intercellular junctions and/or
--- selective membrane permeability

Front 395

How does the blood-brain barrier work? ***

Back 395

design allows:
- selective passage of some substances into/out of the CNS but not others (promotes the exchange of O2, CO2, amino acids, sugars but not other substances such as large proteins

- protection for CNS from foreign substances (toxins) can be a problem when certain medicines are unable to cross

- stable metabolic environment for the CNS

Front 396

Name some types of cerebrovascular disorders. ***

Back 396

- CVA/stroke
- TIA
- hemorrhage

Front 397

What is a CVA? ***

Back 397

- cerebrovascular accident (a.k.a. stroke)

- caused by thrombosis (due to atherosclerosis, arteriosclerosis) or embolism (thrombus, fat globule, air bubble, clump of bacteria)

- occlusion of artery results in ischemia to area of brain supplied and result is infarction

Front 398

What is a TIA? ***

Back 398

- transient ischemic attack
- often called a "mini stroke"

- caused by temporary occlusion of a narrowed vessel (vasospasm, traveling embolis, thrombosis)

- results in reversible neurologic deficits (dizziness, LOC, weakness, difficulty speaking); considered warning signs for impending CVA

Front 399

What are some types of cranial hemorrhage? ***

Back 399

- bleeding secondary to ruptured vessel, also a type of CVA

caused by:
- aneurysms resulting from chronic hypertension, vascular malformations, atherosclerosis, infection
--- named according to location: intracerebral hemorrhage, subarachnoid hemorrhage, or subdural hemorrhage

- tearing of vessels due to trauma
--- named according to location: subdural hematoma (venous) or epidural hemorrhage (arterial)

Front 400

What constitutes the peripheral nervous system (PNS)? ***

Back 400

- consists of all nervous tissue outside the vertebral canal

- formed by nerves leading to and from CNS

- nerves contain axonal fibers which conduct afferent/efferent information
--- cranial nerves 12 (pairs)
--- spinal nerves 31 (pairs) (mixed)

Front 401

Describe the construct of a peripheral nerve from its origin in the spinal cord. ***

Back 401

- spinal cord (in vertebral canal) gives rise to the ventral and dorsal roots at each segmental level
- ventral and dorsal roots are formed bilaterally from cord
--- ventral root consists of outgoing motor axon fibers
--- dorsal root consists of incoming sensory axon fibers

- roots join while in vertebral canal, form a single spinal nerve, pass out of vertebral canal via intervertebral foramen

- once outside of intervertebral canal, spinal nerve immediately splits into 2 branches (rami)
--- anterior (ventral) ramus – innervates autonomic nervous system, BUE/BLE and anterior/lateral aspects of trunk
--- posterior (dorsal ramus) innervates posterior trunk

Front 402

Peripheral nerves contain nerve fibers which innervate both....

Back 402

visceral organs and somatic structures (skeletal muscle, joints, bones, skin)

Front 403

What tissues/structures comprise a peripheral nerve? ***

Back 403

- made up of myelinated and/or unmyelinated axons which transmit either sensory or motor information

- mixed axons (myelinated/unmyelinated/sensory/motor) are each surrounded by a connective tissue sheath called endoneurium (inner) and then are grouped into bundles called fasiculi

- each fasciculus is surrounded by a connective tissue sheath called a perineurium (around)

- entire nerve is comprised of many fasiculi and is surrounded by tough connective tissue sheath called epineurium (over) (contains fat cells and small blood vessels)

Front 404

What is the endoneurium? ***

Back 404

surrounds the individual axon

Front 405

What is the perineurium? ***

Back 405

surrounds the fascicle

Front 406

What is the epineurium? ***

Back 406

surrounds an entire nerve

Front 407

The PNS begins once the nervous tissue exits the _____ ______. ***

Back 407

intervertebral foramen

Front 408

Peripheral nerves are composed of _____ which may be either sensory or motor. ***

Back 408

axons

Front 409

Many fasiculi surrounded and joined together by epineurium comprise a _____ _____. ***

Back 409

peripheral nerve

Front 410

What is a nerve plexus? ***

Back 410

- a network of spinal nerves in one region

- anterior (ventral) rami of the spinal nerves join together, intermingle, split and regroup to form a network

- peripheral nerves are formed from each plexus

- occurs at every level except thoracic (direct innervation)

Front 411

List the four major plexuses. ***

Back 411

- cervical
- brachial
- lumbosacral
- coccygeal

Front 412

Location and innervation:

cervical plexus ***

Back 412

- C1-C4 spinal nerves

- innervates muscles of the neck and diaphragm

Front 413

Location and innervation:

brachial plexus ***

Back 413

- C5-T1 spinal nerves

- innervates muscles of the scapula and UE

Front 414

Location and innervation:

lumbosacral plexus ***

Back 414

- L1-S3 or T12-S3 spinal nerves

- innervates muscles of LE
--- lumbar division (L1-L4) or (T12-L4)
--- sacral division (L4-S3)

Front 415

Location and innervation:

coccygeal plexus ***

Back 415

- S3 – coccyx spinal nerves

- innervates muscles of the genitalia and perineum

Front 416

What major nerves are part of the brachial plexus? ***

Back 416

- C5-T1

- axillary nerve: deltoid, teres minor (C5-6)
- all scapular nerves: scapular muscles (C5-6)

- thoracodorsal nerve: lattisimus dorsi (C6-8)
- pectoral nerve: pectoralis major (C5-T1)

- musculocutaneous nerve: biceps, brachialis, coracobrachialis (C5-C7)

- radial nerve: triceps, wrist/finger extensors, supinator, brachioradialis (C5-C8)
- median nerve: pronators, FCR, FDS, FDP (radial side), thumb opposition, flexion, abduction, lumbricales 1,2 (C6-T1)
- ulnar nerve: FCU, FDP (ulnar side), interossei, lumbricales 4, 5 (C8 – T1)

Front 417

What major nerves are part of the cervical plexus?

Back 417

- vagus nerve (CN X)

- phrenic nerve (to diaphragm)

Front 418

What major nerves are part of the lumbar division of the lumbosacral plexus? ***

Back 418

lumbar division (L1-S3)
- obturator nerve: hip adductors (adductor magnus/longus/brevis)
- femoral nerve: hip flexors, quadriceps

Front 419

What major nerves are part of the sacral division of the lumbosacral plexus? ***

Back 419

sacral division (L4-S3)
- inferior gluteal nerve: gluteus maximus
- superior gluteal nerve: gluteus medius/minimus
- sciatic nerve: hamstrings (tibial branch - all, peroneal branch - biceps femoris short head)
--- tibial nerve: plantar flexors (gastroc, soleus), posterior tibialis
--- common peroneal nerve: no muscles directly
----- superficial peroneal nerve: peroneus longus, peroneus brevis
----- deep peroneal nerve: tibialis anterior, extensor hallucis longus

Front 420

Besides innervating specific muscles, peripheral nerves also...

Back 420

- innervate specific cutaneous areas (which differ from dermatomal areas)

- cutaneous areas (nerve fields) are sensory areas innervated by peripheral nerves

for example:
- axillary nerve innervates lateral arm over lower 2/3 of deltoid
- musculocutaneous nerve innervates lateral surface of forearm
- radial nerve innervates dorsal aspect of lateral half of hand (except dorsum of fingertips 2,3), lateral thumb
- median nerve innervates lateral half of palm and palmar aspect of thumb, digits 2,3,4 (radial side) and dorsum of finger tips 2,3
- ulnar nerve indicates medial half of hand, thumb, digits 2,3,4 (radial side)
- lateral femoral cutaneous nerve innervates anteriolateral aspect of thigh
- anterior femoral cutaneous nerve innervates anterior thigh to just below knee
- obturator nerve innervates middle of medial thigh, medioposterior aspect of thigh and knee
- common peroneal nerve innervates lateral aspect of lower leg just below knee level
- saphenous nerve innervates medial aspect of calf and heel
- superficial peroneal nerve innervates anteriolateral lower leg, dorsum of ankle and foot
- sural nerve innervates posterior calf and lateral half of foot
- deep peroneal nerve innervates triangle over dorsum of distal metatarsal 1 and 2

- tibial nerve (medial/lateral plantar nerve) innervates posteriolateral aspect of lower leg and sole of foot

Front 421

What are some clinical signs and symptoms that indicate injury to a peripheral nerve? ***

Back 421

- PNI results in both sensory and motor impairments

sensory impairment:
- if the area of sensory impairment follows a dermatomal pattern, then lesion is proximal (spinal nerve/nerve root injury); e.g., HNP with spinal nerve root impingement
- if area of sensory impairment follows cutaneous pattern (nerve field) then lesion is distal and is PNI. (e.g., entrapment, trauma, compression)

- loss of sensation (does not necessarily mean absence of sensation)
- paresthesias
- pain
- muscle weakness
- muscle paralysis

Front 422

List some types of PNI. ***

Back 422

- stretch (neurapraxia): shocks nerve, but does not tear; usually heals within 3 months

- neuroma: scar that develops due to injury

- rupture: complete disruption of nerve (requires surgical intervention; graft)

- avulsion: nerve torn from spinal cord

- compression: pressure causes myelin break down (we have to watch out for this/be sure that we are not causing this in many of our treatments)

Front 423

What are some clinical signs and symptoms that indicate injury to a peripheral nerve? ***

Back 423

- PNI results in both sensory and motor impairments

sensory impairment:
- if the area of sensory impairment follows a dermatomal pattern, then lesion is proximal (spinal nerve/nerve root injury); e.g., HNP with spinal nerve root impingement
- if area of sensory impairment follows cutaneous pattern (nerve field) then lesion is distal and is PNI. (e.g., entrapment, trauma, compression)

- loss of sensation (does not necessarily mean absence of sensation)
- paresthesias
- pain
- muscle weakness
- muscle paralysis

Front 424

List some causes of PNI. ***

Back 424

Nerve entrapment/compression due to:
- inflammation/edema of surrounding soft tissue
- bony impingement
- tight cast
- poor positioning
- trauma: lacerations, stretching, fractures
- disease process: viral infection, arthritis, vascular insufficiency

Front 425

List some types of PNI. ***

Back 425

- stretch (neurapraxia): shocks nerve, but does not tear; usually heals within 3 months

- neuroma: scar that develops due to injury

- rupture: complete disruption of nerve (requires surgical intervention; graft)

- avulsion: nerve torn from spinal cord

- compression: pressure causes myelin break down (we have to watch out for this/be sure that we are not causing this in many of our treatments)

Front 426

What are some clinical signs of injury to the axillary nerve? ***

Back 426

impairment in shoulder
- flexion
- extension
- abduction

Front 427

List some causes of PNI. ***

Back 427

Nerve entrapment/compression due to:
- inflammation/edema of surrounding soft tissue
- bony impingement
- tight cast
- poor positioning
- trauma: lacerations, stretching, fractures
- disease process: viral infection, arthritis, vascular insufficiency

Front 428

What are some clinical signs of injury to the musculocutaneous nerve? ***

Back 428

impairment in elbow
- flexion
- supination

Front 429

What are some clinical signs of injury to the axillary nerve? ***

Back 429

impairment in shoulder
- flexion
- extension
- abduction

Front 430

What are some clinical signs of injury to the musculocutaneous nerve? ***

Back 430

impairment in elbow
- flexion
- supination

Front 431

What are some clinical signs of injury to the median nerve? ***

Back 431

impairment in:
- pronation

thumb
- opposion
- flexion
- abduction

Front 432

What are some clinical signs of injury to the radial nerve? ***

Back 432

impairment in:
- elbow extension
- wrist extension
- finger extension
- thumb extension

Front 433

What are some clinical signs of injury to the ulnar nerve? ***

Back 433

impairment in:
- wrist flexion
- finger flexion
- intrinsics

Front 434

What are some clinical signs of injury to the femoral nerve? ***

Back 434

impairment in:
- hip flexion
- knee extension

Front 435

What are some clinical signs of injury to the obturator nerve? ***

Back 435

impairment in:
- hip adduction

Front 436

What are some clinical signs of injury to the sciatic nerve? ***

Back 436

impairment in:
- hip extension
- knee flexion
- actions below (tibial/peroneal)

Front 437

What are some clinical signs of injury to the tibial nerve? ***

Back 437

impairment in:
- plantar flexion
- inversion
- toe flexion

Front 438

What are some clinical signs of injury to the common peroneal nerve? ***

Back 438

impairment in:
- dorsiflexion
- eversion
- toe extension

Front 439

What occurs with compression of the long thoracic nerve? ***

Back 439

- winging of the scapula

(serratus anterior: stabilizes scapula against chest wall)

Front 440

What occurs with entrapment or direct trauma to the radial nerve? ***

Back 440

- drop wrist (usually distal to triceps)

(triceps, wrist and finger extensors affected)

Front 441

What occurs with entrapment/compression of ulnar and median nerves? ***

Back 441

Wrist/finger flexors, intrinsics are affected:
- wrist/finger flexion, abduction/adduction, and flexion of MCP/extension of IPs

- if ulnar nerve only: cubital tunnel = ulnar wrist and hand (claw hand)

- if median nerve only: CTS

Front 442

What two hand deformities can be caused by entrapment/compression of the medial nerve? ***

Back 442

- atrophy of thenar eminence (CTS)

- "benediction hand"

Front 443

What occurs with entrapment of sciatic nerve? ***

Back 443

- piriformis syndrome

affects
- hamstrings
- plantar flexors
- dorsiflexors
- toe flexors and extensors

- deficit: weakness in hip extension, knee flexion, PF, toe flexion

Front 444

What occurs with compression of tibial nerve? ***

Back 444

- popliteal fossa, baker’s cyst

affects:
- triceps surae: tibialis posterior, toe flexors, PF, invertors
- deficits: absence of above actions, no push off with gait

Front 445

What occurs with compression of common peroneal nerve? ***

Back 445

affects:
- peroneals
- anterior tibialis
- toe extensors
- everters
- dorsiflexors

deficits:
- inability to DF foot during gait,
- drop foot,
- steppage gait

Front 446

What occurs with Morton's neuroma? ***

Back 446

enlargement of conjoined lateral and medial plantar nerve may be caused by high heels or pes planus

Front 447

What occurs with diabetic neuropathy? ***

Back 447

- damage to nerves due to elevated blood glucose

- decreased sensation (stocking glove)

- deficits after chemo too.

Front 448

What is the ANS? ***

Back 448

- division of the peripheral nervous system

- consists of efferent and afferent fibers which innervate viscera

- controlled by various areas of the CNS (SC, BS, hypothalamus)

- hypothalamus primary coordinator of ANS functions

Front 449

Which structure is the primary coordinator of ANS functions? ***

Back 449

hypothalamus

Front 450

What is the hypothalamus' role in ANS function? ***

Back 450

receives and integrates information regarding:
- oxygen levels
- blood pressure
- visual, auditory, olfactory
- emotions

- discharges appropriate command to ANS

Front 451

How does information in the ANS get from the spinal cord to the target organ, gland, or smooth/cardiac muscle? ***

Back 451

- via a 2 neuron chain (from spinal cord or brainstem to target structure)

- primary neuron (preganglionic neuron) originates in lateral gray column
- fibers then travel away from spinal cord via ventral ramus and quickly exit.

- at some point fibers synapse with 2nd order neuron (postganglionic neuron) located in autonomic ganglia, at different areas in the PNS, then fibers travel on to target tissue

Front 452

What are the functions of the ANS? ***

Back 452

- innervate smooth muscle (organs, vessels), cardiac muscle, glands

- maintains homeostasis of the organism; keeps internal system in balance

- maintains proper visceral functioning during situations requiring extreme responses

- no volitional control

Front 453

What are the divisions of the ANS? ***

Back 453

- sympathetic

- parasympathetic

Front 454

How are most organs controlled by the sympathetic and parasympathetic nervous systems? ***

Back 454

- majority of visceral structures receive innervation from both

- divisions are antagonistic to one another; each system is constantly firing to visceral structures; with one or the other dominating as the situation requires

- directed by CNS through hypothalamus

Front 455

How does information flow in the ANS? ***

Back 455

- visceral and vascular receptors send information to
--- limbic system
--- hypothalamus
--- reticular formation
--- spinal cord

- which work together, and send information via the
--- sympathetic division,
--- parasympathetic division, or
--- hormonal (endocrine) system)

Front 456

Describe the sympathetic division of the ANS. ***

Back 456

- thoracolumbar (only)

- located at spinal cord levels between T1 and L3

Route:
- lateral horn of spinal cord to ventral root
- exits at communicating ramus (white)
- then to sympathetic trunk (paravertebral ganglia)
- either re-enters spinal nerve
- or travels on to target viscera (cranial or sacral levels, via collateral ganglia, or direct to the adrenal medulla)

Front 457

What is the sympathetic route in path ***
A?
B?
C?

Back 457

- through the paravertebral ganglionic chain and direct to synapse within the adrenal medulla

- via the paravertebral ganglionic chain upward into the cranial region to synapse with the postganglionic neuron (could've gone sacral as well)--sympathetic nerve route

- through the paravertebral ganglionic chain to synapse in a collateral (prevertebral) ganglia (in this case, the celiac) before traveling on to the associated organs--splanchnic nerve route

Front 458

What is the purpose of the sympathetic nervous system? ***

Back 458

- prepares the body for "fight or flight"

- stimulates activity; dominates in stressful situations

- neurotransmitters released at post-ganglionic endings:
--- epinephrine,
--- norepinephrine
--- adrenalin (adrenaline/noradrenaline are the same thing as epinephrine/norepinephrine)
(all secreted by adrenal medulla)

- not mentioned on our slides, but the postganglionic neurons also release acetylcholine (only with sweat glands and some smooth muscle)

Front 459

Describe the parasympathetic nervous system. ***

Back 459

- craniosacral
- located "around" the sympathetic nervous system (cranially and caudally)

- cranial - exits with CN III, CN VII, CN IX, CN X
- sacral - exits spinal cord with sacral nerves to ventral root

- either travels with spinal nerve or to outlying ganglia, or exits at communicating ramus, then travels on to target viscera

Front 460

What is the purpose of the parasympathetic nervous system? ***

Back 460

- basically opposes the sympathetic nervous system
- sets body up to "rest and digest" -- vegetative functions such as feeding and emptying

- conserves and restores energy; dominates in relaxing, restful activity

- neurotransmitters released
--- acetylcholine at both pre and postganglionic synapses

Front 461

How do the sympathetic and parasympathetic nervous systems affect the eye? ***

(She said memorize these!!)

Back 461

S - dilates pupil

P - constricts pupil

Front 462

How do the sympathetic and parasympathetic nervous systems affect the salivary glands? ***

(She said memorize these!!)

Back 462

S - stimulates thick, viscous mucus

P - stimulates watery secretions

Front 463

How do the sympathetic and parasympathetic nervous systems affect the lungs? ***

(She said memorize these!!)

Back 463

S - dilates bronchi and increases respiratory rate

P - constricts bronchi

Front 464

How do the sympathetic and parasympathetic nervous systems affect the heart? ***

(She said memorize these!!)

Back 464

S - increases heart rate and blood pressure

P - decreases HR and BP

Front 465

How do the sympathetic and parasympathetic nervous systems affect the vessels? ***

(She said memorize these!!)

Back 465

S - vasoconstriction

P - dilation (or no effect)

Front 466

How do the sympathetic and parasympathetic nervous systems affect the stomach/intestines? ***

(She said memorize these!!)

Back 466

S - decreases motility

P - increases motility

Front 467

How do the sympathetic and parasympathetic nervous systems affect the liver? ***

(She said memorize these!!)

Back 467

S - stimulates glycogen breakdown

P - no effect

Front 468

How do the sympathetic and parasympathetic nervous systems affect the adrenal glands? ***

(She said memorize these!!)

Back 468

S - stimulates release of epinephrine

P - no effect

Front 469

How do the sympathetic and parasympathetic nervous systems affect the pancreas? ***

(She said memorize these!!)

Back 469

S - no effect

P - increases secretion

Front 470

How do the sympathetic and parasympathetic nervous systems affect the bowel and bladder? ***

(She said memorize these!!)

Back 470

S - contracts sphincters

P - inhibits sphincters

Front 471

Describe the actions that would be taken by the ANS in the case of an appendicitis attack. ***

Back 471

- autonomic fibers carry info to BS, hypothalamus, limbic system (divergence of neuron carrying incoming pain signal)

- pain referred to umbilical region (looks like by a long reflex arc?)
- sympathetic efferents inhibit peristalsis (again, long reflex arc?)

- somatic efferents cause abdominal muscle contraction
(because of close proximity of neurons)

Front 472

List some special feedback systems. ***

Back 472

- visual system
- auditory system
- vestibular system
- reticular formation
- limbic system

Front 473

What components comprise the visual system? ***

Back 473

consists of:
- muscles controlling eye movement
- optical components (eyeball, cornea, iris, lens, and retina)
- optic nerve
- optic chiasm (where optic nerves cross)
- optic tract
- visual cortex/association areas (occipital lobe)

Front 474

What are the functions of the visual system? ***

Back 474

- detects light and differences in light patterns (shapes, color, movement)

- transforms information into electrical impulses which travel to the visual cortex where the signals are decoded and we “see” and recognize objects

- light passes through optical components of the eyeball
--- special sensory receptors (rods and cones/approximately 126 million receptors)
transform light rays and color spectrum into electrical signals
--- transmitted along the optic nerve from each eye, decussate and form the R and L optic tract

- each optic tract carries fibers from half of each retina
- tracts travel to brainstem
- from brainstem to cortex/visual association areas (occipital lobes)

Front 475

How do the visual pathways function? ***

Back 475

- visual information from the right visual field activates neurons in the left half of the retina of both eyes

- axons from the temporal half of the retina project ipsilaterally, while axons from the nasal half of the retina cross the midline in the optic chiasm to project to the contralateral side

Front 476

What is the visual field and how is it created? ***

Back 476

- amount of the world you see at anyone time, without eye or head movements

- lateral (temporal) and medial (nasal) halves in each eye work together to produce a R and L visual field

Front 477

For what kinds of behaviors are visual and vestibular information important? ***

Back 477

- generating eye movements which allow observation of a moving or stationary object

- maintaining an upright posture

- keeping track of your own position in space

Front 478

List some disorders of the visual system. ***

Back 478

- ptosis (droopy eyelid)
- strabismus (misalignment)
- diplopia (double vision)

- lesions to CN III, IV, or VI affect movement of eyes and eyelids
- cataracts (clouded lens)

- visual field deficits (binasal hemianopia, bitemporal hemianopia, homonymous hemianopia)
- cortical blindness (cannot interpret input)

Front 479

What are cataracts? ***

Back 479

- most common cause of blindness in U.S.
- lens becomes clouded due to aging, infection, trauma, or UV exposure)
- can be surgically corrected

Front 480

What is binasal hemianopia? ***

Back 480

medial half of visual field impaired, resulting in no central vision

(#2 is bitemporal hemianopia--the opposite/inverse would be binasal hemianopia)

Front 481

What is bitemporal hemianopia? ***

Back 481

lateral half of visual fields impaired resulting in tunnel vision; no peripheral vision

(# 2 is bitemporal hemianopia)

Front 482

What is homonymous hemianopia? ***

Back 482

defect in temporal half of one eye and nasal half of other eye resulting in loss of either the R visual field or the L visual field (occurs with some CVA patients)

(#3 is homonymous hemianopia)

Front 483

Name the pictured visual field deficits. ***

Back 483

- right optic nerve lesion
- bitemporal hemianopia (opposite would be binasal hemianopia)
- homonymous hemianopia
- left inferior homonymous quadrantanopia due
to right temporal lobe lesion

Front 484

What is cortical blindness? ***

Back 484

- appropriate electrical impulses are delivered to visual cortex (occipital lobe)

- information cannot be decoded; patient cannot interpret visual information

Front 485

Which areas of the cortex direct eye movements? ***

Back 485

(see picture)

Front 486

What structures comprise the auditory system? ***

Back 486

- external ear (pinna, external auditory meatus)
- middle ear (ear drum/tympanic membrane, ossicles)
- inner ear (cochlear duct/cochlea, organ of Corti)

- cochlear division of CN VIII

- ear is a transducer

Front 487

How does the auditory system function? ***

Back 487

- ear is a transducer
- transforms mechanical energy (vibrations) into electrical impulses which travel to the auditory cortex where the signals are decoded and we “hear” sounds

- sound waves converge through outer ear and strike tympanic membrane
--- vibrations of membrane transmitted by way of ossicles to cochlear duct
--- vibrations stimulate hair cells in organ of Corti by way of mechanical distortion
--- electrical signals travel along the cochlear nerve to brainstem

- from brainstem, signals transmitted to various regions of CNS
--- reflex nuclei in BS (response to strong, sudden sounds causing reflex turning of head toward sound)
--- cerebellum
--- reticular formation
--- thalamus
--- auditory cortex/association areas of temporal lobe

Front 488

List some common disorders of the auditory system. ***

Back 488

- tinnitus
- deafness

Front 489

What is tinnitus? ***

Back 489

ringing, buzzing, or roaring noises in the ear (can be early sign of cochlear disease) more of a symptom than a pathology

Front 490

What is deafness? ***

Back 490

- conduction deafness (external/middle ear damage)
- nerve deafness (inner/cochlear nerve damage)

Front 491

What structures comprise the vestibular system? ***

Back 491

- vestibular labyrinth located in inner ear (3 semicircular canals containing endolymph fluid)

- special receptor organs covered with hair cells (located within the labyrinths)

- vestibular divisions of CN VIII

Front 492

What are the functions of the vestibular system? ***

Back 492

- proprioceptive system of the head
- detects head position/movement

- stimulation of receptor organs occurs with head position/movement and
- electrical signals are transmitted along the vestibular nerve to brainstem
- from brainstem signals are transmitted to various regions of CNS

- information received used for:
--- posture
--- eye movements
--- control of equilibrium
--- spatial orientation

Front 493

From the brainstem, vestibular system information is transmitted to where? ***

Back 493

- vestibulospinal tract (reflex responses with result in extension patterns in trunk/extremities with rapid change in head position)

- cerebellum
- CN III, IV, VI for eye movements (keeps eyes constant in relation to environment during movement of head)

- reticular formation
- thalamus
- postcentral gyrus and sensory association areas (parietal lobe)

Front 494

To which other systems is the vestibular system closely related? ***

Back 494

- auditory system (physical location)

- visual system (function)

Front 495

List some common disorders of the vestibular system. ***

Back 495

- nystagmus (involuntary oscillation of eyeballs)

- vertigo (illusionary sensation of moving about in space or of objects moving about; disorientation in space)

Front 496

Describe the vestibular apparatus. ***

Back 496

- consists of the utricle, saccule, and semicircular canals
- three semicircular canals are at right angles to each othe
- each semicircular canal has a swelling, the ampulla, which contains a receptor mechanism, the crista

- bending of the hair cells changes pattern of firing in the vestibular neurons
- inside the utricle and saccule is a receptor called the macula
- in the macula, hairs projecting from hair cells are embedded in a gelatinous material

- atop the gelatinous material are otoconia: small, heavy, sandlike crystals
- when the macula is moved into different positions, weight of the otoconia bends the hairs, stimulating the hair cells and changing the pattern of vestibular neuron firing.

Front 497

What is the reticular formation? ***

Back 497

- vast complex of intermingled gray and white matter extending through entire brainstem, hypothalamus, thalamus and projection fibers to cortex (varying spots, not an actual “formation”)

- multiple interconnections with various aspects of the nervous system

- projects fibers to spinal cord via reticulospinal tract

Front 498

What are the functions of the reticular formation? ***

Back 498

- regulation of arousal, level of consciousness, and sleep (multiple interconnections with various sensory pathways; auditory, visual, visceral, and somatosensory)

- contributes to input for postural control and reflexes via communication with cerebellum, vestibular system, and reticulospinal tract
- contributes to some autonomic functions via respiratory and BP reflex centers in brainstem

- performance of motor tasks is influenced by level of alertness (related—increase your alertness, enhance performance/ability to respond)
- reticular system affects movement:
--- interconnections with cortex and reticulospinal tract
- high arousal state = alert, quick to respond with or to movements
- low arousal state = slowed responses, movements tend to be sloppy (groggy, sleepy)

Front 499

List some disorders of the reticular system. ***

Back 499

- TBI
- infections
- tumors
- profound loss of consciousness: coma

(coma may also occur with extensive damage to cortex and extracranial injuries)

Front 500

What structures comprise the limbic system? ***

Back 500

- limbic cortex deep in cerebral cortex; includes portions of temporal and frontal lobes
- contains some of the most primitive/ancient portions of cerebrum

- linked up with prefrontal cortex, temporal lobe, hypothalamus/autonomic nervous system, basal ganglia, and reticular formation
- olfactory system closely linked to many limbic structures

Front 501

What are some functions of the limbic system? ***

Back 501

- contribute to species survival

- olfactory system closely associated:
--- feeding behavior
--- sexual behavior
--- aggression
--- expression of emotion
--- conversion of memory (short-term to long-term memory)

Front 502

How does the limbic system affect movement? ***

Back 502

- interconnects with hypothalamus which links with ANS to deal with stresses; keeps body “revved up”

- interconnects with basal ganglia to integrate long-term memory of movement

- interconnects with reticular formation to link effects of moods and emotions on movement (happy moods increase level of arousal; depressed moods decrease arousal level)

Front 503

What are some signs and symptoms of limbic system lesions? ***

Back 503

- mood personality disorders believed to originate in the limbic system (schizophrenia, depression, anxiety, phobias, and hypersexuality)

- long-term memory deficits (amnesia)

- eating disorders
- olfactory disorders (loss of smell, perverted smell and smell hallucinations)
- temporal lobe epilepsy

Front 504

Pyramidal system ***

Back 504

motor cortex and corticospinal tract

Front 505

Extrapyramidal system ***

Back 505

basal ganglia and other subcortical structures/tracts influencing motor commands:
- rubrospinal,
- reticulospinal and
- vestibulospinal tracts

Front 506

Motor system ***

Back 506

consists of
- cortical and subcortical gray matter,
- descending efferent tracts, and
- PNS

Front 507

If a person has a lesion in the given area, state the effect on discriminative touch and conscious proprioceptive information: ***
- cerebrum, midbrain, pons, upper medulla?
- lower medulla?
- spinal region?
- peripheral region?

Back 507

- contralateral loss
- ipsilateral loss
- ipsilateral loss
- ipsilateral loss

Front 508

Describe the motor functions of the cortical gray matter. ***

Back 508

- motor cortex (primary motor cortex, precentral gyrus, premotor areas)
- concerned with purposeful movement, complex, simultaneous movements (extremities, speech)

- somatotopic organization in primary motor cortex (homunculus)
- areas are conscious level of motor programming (initiation)

Front 509

Describe the structure and motor functions of the subcortical gray matter. ***

Back 509

subcortical components
- basal ganglia
- cerebellum
- parts of diencephalon
- parts of brainstem

basal ganglia collaborates with cerebral cortex through a system of feedback loops initiating movement
- contributes to motor programming
- contributes to motor modification

cerebellum collaborates with the
- vestibular system,
- proprioceptive information from the PNS, and
- motor cortex;
responsible for balance, muscle tone, coordination

areas of diencephalon and brainstem also collaborate with above systems in motor programming

- these areas are the unconscious level of motor programming

- motor cortex, basal ganglia, cerebellum, etc. are linked to each other; extensive communication between all of them to program motor commands for coordinated, skilled, volitional movements

Front 510

Describe the corticobulbar/corticospinal descending tracts (pyramidal system.) ***

Back 510

- originate at primary motor cortex region in precentral gyrus
- direct route to lower motor neuron (LMN) in brain stem or spinal cord; part of the “final common pathway for motor command”
- gives branches to cerebrum for error correction

- pyramidal system - concerned with initiation of purposeful movements

Front 511

Describe the rubrospinal, reticulospinal, and vestibulospinal descending tracts (extrapyramidal system.) ***

Back 511

extrapyramidal system
- rubrospinal,
- reticulospinal, and
- vestibulospinal tracts

- originate from brainstem nuclei to LMN
- important for balance responses, postural control during movement, and some hand and finger movements

Front 512

What are lower motor neurons? ***

Back 512

- anterior (ventral) horn cells and cranial nerve nuclei
- motor neurons located in gray matter of brainstem and spinal cord

- the LMN is “final common pathway” for motor commands
- receives direct input from both pyramidal and extrapyramidal systems
- axons travel via peripheral nervous system to skeletal muscles

- final motor command route to muscles for all movement (voluntary and reflexive)

Front 513

Describe the two types of LMNs. ***

Back 513

- alpha motor neurons: innervate skeletal muscle

- gamma motor neurons: innervate muscle spindles of skeletal muscles

Front 514

Describe a motor unit. ***

Back 514

an alpha motor neuron and all the muscle fibers it innervates

(the picture depicts two motor units)

Front 515

Special sensory endings (dendritic receptors) for the somatosensory system are located where in the body? ***

Back 515

- skin, tendons, joints
- organs, blood vessels
- eyes, tongue, nose
(to name a few)

Front 516

What are the four types of sensation? ***

(She definitely said to know these!!)

Back 516

- superficial (somatosensory)
- deep (somatosensory)
- visceral
- special senses

Front 517

What types of sensation does the somatosensory system deal with? ***

Back 517

- superficial and deep systems

- pain
- temperature
- light touch
- deep touch
- vibration
- proprioception

Front 518

What structures comprise the somatosensory system? ***

Back 518

- special sensory receptors and their neuronal connections,
- ascending tracts,
- thalamus,
- primary somatosensory cortex, and
- related association areas

Front 519

What are receptors? ***

Back 519

specialized cells for detecting particular changes in both the internal and external environment

Front 520

Special sensory endings (dendritic receptors) for the somatosensory system are located where in the body? ***

Back 520

- skin, tendons, joints
- organs, blood vessels
- eyes, tongue, nose
(to name a few)

Front 521

What are the four types of sensation? ***

(She definitely said to know these!!)

Back 521

- superficial (somatosensory)
- deep (somatosensory)
- visceral
- special senses

Front 522

What types of sensation does the somatosensory system deal with? ***

Back 522

- superficial and deep systems

- pain
- temperature
- light touch
- deep touch
- vibration
- proprioception

Front 523

What structures comprise the somatosensory system? ***

Back 523

- special sensory receptors and their neuronal connections,
- ascending tracts,
- thalamus,
- primary somatosensory cortex, and
- related association areas

Front 524

What are receptors? ***

Back 524

specialized cells for detecting particular changes in both the internal and external environment

Front 525

How many types of stimuli is each special receptor capable of detecting? ***

Back 525

each special receptor is designed to detect a specific type of stimuli
(e.g., Pacinian corpuscle detects pressure; temperature would not affect it)

Front 526

How is intensity of a stimulus imparted? ***

Back 526

- intensity of stimuli is signaled by how many action potentials pass along each second

Front 527

All sensory information is carried via what route, and from which starting point to which ending point? ***

Back 527

- all sensory information is carried in nerves by action potentials

- from receptors to cell bodies (dorsal root ganglia) of dorsal root to
- posterior horn in spinal cord to
- CNS (and, if indicated, through reflex arc at spinal cord level)

Front 528

How many types of sensory receptors are there? Name them. ***

Back 528

- interoceptors
- exteroceptors
- proprioceptors

Front 529

What are interoceptors? ***

Back 529

- located deep in viscera and vessels,
- receive stimuli regarding body’s internal changes, such as BP, blood sugar, O2 levels

Front 530

What are exteroceptors? ***

Back 530

- a.k.a. cutaneous receptors
- located superficially in skin layers;
- receive stimuli from external environment regarding pain, temperature, light touch, pressure

Front 531

What are proprioceptors? ***

Back 531

- located deep in muscle/tendon/joints;
- receive stimuli regarding deep pressure, vibration, position sense and movement sense (kinesthesia)

Front 532

Which ascending tracts have we been concerned with? ***

Back 532

- spinothalamic tracts
- dorsal columns
- spinocerebellar tracts

Front 533

What is the function of the spinothalamic tracts?

Back 533

- transmits sensory information on pain, temperature, crude touch (know you're being touched, but not sure where)

- crosses in spinal cord (2-3 levels above incoming spinal segment) synapses in thalamus

Front 534

What is the function of the dorsal columns? ***

Back 534

- transmit conscious proprioception, vibration, discriminative touch (don’t cross until brainstem)

- travels ipsilaterally in posterior column, crosses in brainstem; synapses in thalamus

Front 535

What is the function of the spinocerebellar tracts? ***

Back 535

- transmits unconscious proprioception (movement and position sense)

- dorsal spinocerebellar tract travels ipsilaterally in lateral column; synapses in cerebellum

- ventral spinocerebellar tract crosses and travels contralaterally in lateral column; synapses in cerebellum

- spinocerebellar tracts– not just one place (dorsal & ventral)

Front 536

What two proprioceptors in the muscles have we looked at? ***

Back 536

- muscle spindles

- Golgi tendon organs

Front 537

What is the structure and function of a muscle spindle? ***

Back 537

- located in muscle belly

function:
- detect muscle length and rate of change in length, allowing
--- fine adjustments with muscle contractions and loading
--- protection of muscle from extreme stretch (tearing)
- when muscle stretches, spindle stretches

consists of:
- special muscle fibers (intrafusal fibers--nuclear chain and nuclear bag)
- 3-5 within a sheath;
- innervated by gamma motor neuron
- entire structure called a spindle
- spindles lie parallel to, within, and attached to regular muscle fibers (extrafusal fibers)
- spindles stimulate with stretch of extrafusal muscle fibers
- when muscle stretches, spindle stretches, and action potentials are fired to DRG then to posterior horn (spinal cord/brain)
--- at spinal cord level, produces stretch reflex response if necessary
--- at higher centers, makes necessary adjustments to muscle loading

Front 538

How do gamma motor neurons control muscle spindles? ***

Back 538

- in order for muscle spindle to stay taut and ready to respond to loading/lengthening changes on muscle, spindle must stay contracted, this is controlled by the gamma motor neuron

- gamma motor neuron continuously receives stimuli to contract intrafusal muscle fibers; this keeps spindle taut and ready to react to lengthening or rate of lengthening of extrafusal muscle fibers so that proper sensory feedback is sent to CNS and adjustments are made

Front 539

How do muscle spindles work? ***

Back 539

muscle spindles consist of:
- intrafusal fibers innervated by gamma motor neurons (muscle spindle)

- extrafusal fibers innervated by alpha motor neurons (muscle fibers)

To correspond with above picture:

A. During passive stretch, spindles are elongated as the muscle is stretched. This stretch activates the spindle sensory receptors. The arrow indicates action potentials transmitted by the type Ia afferent.

B. Excitation of the alpha motor neuron via the corticospinal neuron results in contraction of the extrafusal muscle fibers. If the gamma motor neurons do not fire when the alpha motor neurons to the extrafusal muscles fire, the intrafusal central region will be relaxed and the afferent neurons inactive. This does not occur in a normal neuromuscular system.

C. Normally, during active muscle contraction, alpha and gamma motor neurons are simultaneously active. The firing of gamma motor neurons causes the ends of intrafusal fibers to contract, thus maintaining the stretch on the intrafusal central region and preserving the ability of the sensory endings to indicate stretch.
Muscle spindle has to reset (quick stretch-muscle contracts; to stretch, needs to be slow)

Front 540

Describe the structure and function of the Golgi tendon organ. ***

Back 540

- located in musculotendinous junction

function is to
- detect muscle shortening/tension with muscle contractions
- prevent muscle from exerting so much tension that it avulses from bone

consists of:
- special sensory fiber ending located in musculotendinous regions
- lie in series with muscle fibers

Front 541

How do contraction and stretching of muscles affect the GTO? ***

Back 541

when muscle is contracted, GTOs are stretched/stimulated
- action potentials fired to DRG
- then to posterior horn (spinal cord/brain)
- at spinal cord level, inhibits alpha motor neuron of agonist = muscle relaxes

extreme stretching stimulates GTO
- action potentials fired to DRG
- then to posterior horn (spinal cord/brain)
- at spinal cord, results in excitation of alpha motor neuron of agonist = muscle contraction

Front 542

Why is sensory feedback from all muscles/tendons to the CNS important? ***

Back 542

proper control of muscle function requires continuous sensory feedback so that proper muscle loading adjustments and muscle responses can be made to the environment (to avoid tears, avulsions, ensure muscles are properly functioning, etc.)

Front 543

Describe the structure and function of the thalamus. ***

Back 543

- subcortical gray matter

- majority of sensory information converges in this region

- after synapses; networks with primary sensory cortex and other sensory association areas (cortical gray matter)

(more than a sensory relay station, does have impact on motor movement)

Front 544

What is the function of the cortical gray matter. ***

Back 544

- sensory cortex regions (parietal, occipital, temporal lobes)
- somatotopic organization in primary somatosensory cortex

- all association areas network with one another
- integrated sensory information fed to motor regions

Front 545

List some common motor deficits. ***

Back 545

(these may appear together or independently of each other)

- paralysis/paresis - loss of movement or weakness
- spasticity: hypertonicity
- rigidity: hypertonicity

- involuntary movements - uncontrolled, purposeless, and/or uncoordinated
- abnormal reflexes

- synergies
- associated reactions

Front 546

List some common sensory deficits. ***

Back 546

- analgesia
- hypalgesia
- hyperalgesia
- anesthesia
- hyperesthesia
- paresthesia

- referred pain
- referred visceral pain

Front 547

Describe some of the mechanisms behind paralysis/paresis - loss of movement or weakness. ***

Back 547

- precentral gyrus damage – somatotopic organization; contralateral deficits (R CVA-L hemiparesis)

- spinal cord damage – corticospinal tract interrupted; ipsilateral deficits

- peripheral nerve damage – deficits to muscles innervated by that nerve

Front 548

Describe the mechanisms behind hypertonicity: spasticity. ***

Back 548

- loss of cortical inhibition over lower level reflexes
- usually accompanies paralysis
- usually damage of corticospinal tract
--- clonus,
--- clasp knife phenomenon (increased resistance of extensors to passive flexion, gives way abruptly if resistance stopped; like closing a pocket knife--it's hard at first, but as you get to the point the blade is almost back in the handle, it quickly snaps in)

Front 549

Two divisions of hypertonicity (increased tone) ***

Back 549

- spasticity
--- ususally indicates corticospinal tract disease
--- rate and force dependent (e.g., clasp knife phenomenon)

- rigidity
--- usually indicates basal ganglia disease
--- not rate and force dependent (e.g., lead pipe--same resistance throughout)

Front 550

Describe the mechanisms behind hypertonicity: rigidity. ***

Back 550

- loss of cortical inhibition over lower level reflexes

- damage of basal ganglia;
--- tremor in conjunction with rigidity (cogwheel feel to passive movement) or
--- lead pipe rigidity (rigid, but not jerky movement)

- damage to brainstem
--- decerebrate rigidity: extensor tone entire body
--- decorticate rigidity: extensor tone BLE, BUE flex tone

Front 551

Describe the mechanisms behind involuntary movements: uncontrolled, purposeless, and/or uncoordinated movements. ***

Back 551

- lesions to cerebellum or extrapyramidal system

- cerebellum; intention tremor, ataxia, dysmetria, dysarthria

- basal ganglia: resting tremor, chorea, athetosis, hemiballismus

Front 552

Describe the mechanisms behind hyperreflexia ***

Back 552

- CNS damage/disease
- reflexes no longer overridden
- may become dominant during movement

Front 553

Two types of abnormal reflexes. ***

Back 553

- hyperreflexia

- hyporeflexia

Front 554

Describe the mechanisms behind hyporeflexia ***

Back 554

- PNS damage/disease
- reflex arc interrupted at spinal cord level
- diminished or absent reflexes

Front 555

Describe the mechanisms behind synergies. ***

Back 555

- stereotyped mass pattern of movement of muscle groups instead of isolated movements (total flexion/extension patterns)
- damage to CNS

(Decerebrate, decortical)

Front 556

Describe the mechanisms behind associated reactions. ***

Back 556

- abnormal automatic responses of involved limb with action occurring in another part of the body

- damage to CNS

(Example she gave was of something that started with Soqu.... in which a CVA pt has fingers locked in flexion, but if the therapist lifts shoulder above 90 degrees the fingers let go)

Front 557

What is analgesia? ***

Back 557

complete loss of pain sensation

Front 558

What is hypalgesia? ***

Back 558

decreased sensitivity to pain

Front 559

What is hyperalgesia? ***

Back 559

increased sensitivity to pain

Front 560

What is anesthesia? ***

Back 560

complete loss of sensation

Front 561

What is hyperesthesia? ***

Back 561

increased sensitivity to sensory sensation

Front 562

What is paresthesia? ***

Back 562

abnormal sensation such as numbness, prickling, tingling, often without any apparent cause

Front 563

Describe the mechanism behind referred pain. ***

Back 563

- pain perceived elsewhere than at its true site (much of pain sensation is referred)

- spinal segment sensory damage – dermatomal distribution
- peripheral nerve sensory damage – cutaneous sensory distribution

Front 564

Describe the mechanism behind referred visceral pain. ***

Back 564

- neuronal cell bodies in the posterior horn which receive noxious sensations from afferents in the skin also receive input from nociceptors in the viscera.

- when the visceral nociceptors receive a strong stimulus, cortex often misinterprets the source and identifies the stimulus as coming from a cutaneous region instead of the distant visceral area

- e.g., LUE pain associated with MI

Front 565

What is "language"? ***

Back 565

- communication and comprehension of abstract ideas through the interpretations of symbols

symbols can be:
- gestural
- verbal
- written
- conceptual (thinking abstractly)

Front 566

What is "speech"? ***

Back 566

- verbal expression of one’s thoughts

- requires the coordination of the larynx, mouth, lips, tongue

- which are controlled by specific cranial nerves in brainstem and cortex regions

Front 567

Which cerebral hemisphere is dominant for speech and language for the majority of the population? ***

Back 567

- majority of population is L hemisphere dominant for speech and language function (95%)

- most R handed persons and
- 70% (some studies say 30-40%) of L handed persons are L hemisphere dominant for speech and language

Front 568

Where are the motor areas for speech and language output? ***

Back 568

- language output areas
--- speech
--- handwriting
--- gestures

- frontal lobe, premotor area

Front 569

Where are the motor areas for handwriting and gesturing? ***

Back 569

- handwriting/gesturing area

- converts language codes from other assoc. areas into complex motor commands for handwriting

- premotor area, very near primary motor area for hand/fingers

Front 570

Where is the primary motor area for speech? What is it called? ***

Back 570

- speech area (Broca’s)

- converts language code from other assoc areas into motor commands for speech

- premotor area very near primary motor area for mouth, tongue, throat, and face

Front 571

Where are the primary motor areas of the cerebral cortex and what are their functions? ***

Back 571

- primary motor cortex - voluntarily controlled movements
- premotor area - control of trunk and girdle muscles; anticipatory postural adjustments

- supplementary motor area - initiation of movement; orientation planning; bimanual and sequential movements
- Broca's area - motor programming of speech (usually in the left hemisphere only)

- area analogous to Broca's in opposite hemisphere - planning nonverbal communication (emotional gestures, tone of voice); usually in the right hemisphere

Front 572

Where are the sensory areas for speech and language? ***

Back 572

- language input areas (tactile, auditory, visual)

- association areas of parietal, temporal lobes, occipital lobe

Front 573

Where is the tactile association area and what is its function? ***

Back 573

- parietal lobe: association area very near primary somatosensory area

- interprets objects felt as language

Front 574

Where is the auditory association area and what is its function? ***

Back 574

- temporal lobe: Wernicke’s area

- interprets sound as language

Front 575

Where is the visual association area and what is its function? ***

Back 575

- occipital lobe: association area

- interprets objects/symbols seen as language

Front 576

Describe the central speech area, and the flow of information during conversation. ***

Back 576

consists of
- Broca’s area in the frontal lobe
- Wernicke’s area in the temporal lobe
- interconnecting subcortical bundle of fibers: arcuate fasciculus

- all related motor and sensory association areas are interconnected with white matter pathways
- these pathways travel between the different lobes in the dominant hemisphere
- majority of the population = Left hemisphere

Front 577

What is aphasia, and what is its cause? ***

Back 577

- partial or complete loss of speech/language functions

- due to cortical damage to specific language areas:
---reception (comprehension) of language code – loss of auditory or reading comprehension and/or
--- expression of language code – loss of speech, handwriting, or gesturing

Front 578

What are the four types of aphasia? ***

Back 578

- expressive aphasia (Broca's aphasia)
- receptive aphasia (Wernicke's aphasia)

- global aphasia
- conduction aphasia

Front 579

What is expressive aphasia? ***

Back 579

- a.k.a. Broca’s aphasia

- damage to Broca’s area, motor area for speech, premotor area

- good comprehension of language (written, spoken, gestured)
- difficulty speaking or producing appropriate words
- components of speech articulation are intact (larynx, muscles)

- must communicate with gestures, communication boards, sometimes handwriting
- patient aware of deficit and very concerned or frustrated

Front 580

What is receptive aphasia? ***

Back 580

- a.k.a. Wernicke’s aphasia

- damage to Wernicke’s area, sensory association area of temporal lobe

- impaired language comprehension and repetition
- cannot interpret sounds as meaningful language

- verbalization is fluent but doesn’t make sense (“word salad”), rambling
- often patient is unaware

Front 581

What is global aphasia? ***

Back 581

- damage to central speech area (Broca’s, Wernicke’s, arcuate fasiculus)

- combination of both expressive and receptive aphasias
- loss of language comprehension

- most severe of aphasias

Front 582

What is conduction aphasia? ***

Back 582

- damage to arcuate fasiculus; disconnects Wernicke’s area from Broca’s area
- repetition is severely impaired; naming usually impaired ("Repeat after me." "What is this?")

- comprehension of spoken language is intact
- verbal output is fluent, but can be paraphasic (incoherent, misuse of words)

Front 583

What is dysarthria? ***

Back 583

- disorder of the motor components for speech
- slurred speech

- syntax (phrasing or words) intact
- caused by damage to:
--- cerebellum
--- PNI to cranial nerves which innervate larynx, tongue, lips, face
(CN V, VII, IX, XII)

Front 584

What is agnosia? ***

Back 584

- “gnosia” – knowledge

- inability to recognize/interpret familiar objects although sensory pathway is intact (via visual, auditory, tactile)

- damage to a specific sensory association area while other association areas are intact

Front 585

List three types of agnosia. ***

Back 585

- tactile agnosia
- auditory agnosia
- visual agnosia

Front 586

What is tactile agnosia and what causes it? ***

Back 586

- astereognosis

- inability to recognize objects by handling them but can recognize with visual or auditory input

- damage to tactile association area, dominant parietal lobe

Front 587

What is auditory agnosia and what causes it? ***

Back 587

- inability to recognize sounds as language but can with vision and tactile

- damage to Wernicke’s area, dominant temporal lobe association area

Front 588

What is visual agnosia and what causes it? ***

Back 588

- inability to recognize familiar objects with intact vision but can with auditory and tactile

- damage to dominant occipital lobe association areas

Front 589

Where are the primary sensory areas of the cerebral cortex? ***

Back 589

(see photo)

Front 590

What are the results of lesions to the primary sensory areas of the cerebral cortex? ***

Back 590

(see photo)

Front 591

Where are the sensory association areas of the cerebral cortex? ***

Back 591

(see photo)

Front 592

What are the results of lesions to the sensory association areas of the cerebral cortex? ***

Back 592

(see photo)

Front 593

What is apraxia and what causes it? ***

Back 593

- “praxia” = action

- inability to carry out a complex or skilled motor act upon request although sensory and motor function are intact

- results from interruptions of pathways between association areas
(e.g., unable to touch nose upon request, but could scratch nose easily if it itched)

Front 594

What are the results of lesions in the association cortex? ***

Back 594

(see photo)

Front 595

What are "the four As" of damage to the cerebral cortex? ***

Back 595

- aphasia
- apraxia
- agnosia
- asterognosis

Front 596

What are the three types of memory? ***

Back 596

- immediate recall
- short-term memory
- long-term memory

Front 597

What is immediate recall and with what area of the brain is it associated? ***

Back 597

- sensory memory
retention of information that has been stored for a few seconds
- auditory/visual association areas

Front 598

What is short-term memory and with what area of the brain is it associated? ***

Back 598

- retention of unrehearsed information for 30-60 secs
- retention of rehearsed information for several hours to a few days
- temporal lobe region

Front 599

What is long-term memory and with what area of the brain is it associated? ***

Back 599

- retention of information for weeks, months, years

- structures of limbic system involved with converting short-term memory to long-term memory

Front 600

How is the memory of a patient with brain damage frequently affected? ***

Back 600

- a patient with brain damage to any of the memory areas
(auditory/visual association area, temporal lobe, limbic system) can exhibit memory deficits, often short-term memory deficits.

- these deficits interfere with learning of new skills in rehabilitation

Front 601

What are three other types of memory? ***

Back 601

- emotional memory
- declarative memory
- procedural memory

Front 602

What is emotional memory and with what brain structure is it associated? ***

Back 602

- related to feelings

- amygdala for fear, structures unknown for other emotions

Front 603

What is declarative memory and with what brain structure is it associated? ***

Back 603

- related to facts, events, concepts, locations

- cerebral cortex and hippocampus

Front 604

What is procedural memory and with what brain structure is it associated? ***

Back 604

- skilled movements and habits

- frontal cortex, thalamus, basal ganglia