Neuroscience Exam 2

Front 1

specialized nerve cells or nerve cell terminals that are able to detect specific stimuli

Back 1

sensory receptors

Front 2

sensory receptors that detect outside stimuli

Back 2

exteroceptors

Front 3

sensory receptors that detect inside stimuli

Back 3

enteroceptors

Front 4

the region of space where receptor will respond to adequate stimulus

Back 4

receptive field

Front 5

the conversion of the original form of energy into electrical energy (action potential)

Back 5

stimulus transduction

Front 6

graded change in membrane potential that requires a sufficient amplitude to trigger an action potential

Back 6

receptor potential

Front 7

the four attributes of a physical stimulus

Back 7

modality, intensity, duration, location

Front 8

type or form of energy

Back 8

modality

Front 9

level of stimulation; coded by frequency of action potentials

Back 9

intensity

Front 10

tells us how long the stimulus is present, whether the receptors are slow or fast adapting

Back 10

duration

Front 11

sensitivity of the region depends on receptor __

Back 11

density

Front 12

the minimal interstimulus distance required to perceive two simultaneously applied stimuli as distinct

Back 12

2-point discrimination

Front 13

these fibers transmit information from the periphery to the spinal cord, then to the brain

Back 13

sensory afferents

Front 14

the cell bodies of the sensory afferents are located here

Back 14

dorsal root ganglion

Front 15

the axons of the sensory afferent axons terminate on the interneurons in the __ __

Back 15

dorsal horn

Front 16

these sensory afferents are 13-22 micrometers in diameter, conduct at a rate of 70-120 m/s, and primarily function as alpha motor neurons and muscle spindle primary endings

Back 16

Aa; Ia, Ib

Front 17

these sensory afferents are 8-13 micrometers in diameter, conduct at 40-70 m/s, and function in touch, kinesthesia, muscle spindle secondary endings

Back 17

AB, II

Front 18

these sensory afferents are 4-8 micrometers, conduct at 15-40 m/s, and function in touch, pressure, and gamma motor drive

Back 18

Agamma

Front 19

these sensory afferents are 1-4 micrometers in diameter, conduct at 5-15 m/s, and function in pain, crude touch, pressure, and temperature

Back 19

Adelta, III

Front 20

these sensory afferents are 1-3 micrometers, conduct at 3-14 m/s, and function as pre-ganglionic autonomics

Back 20

B

Front 21

these sensory afferents are 0.1-1 in diameter, conduct at 0.2-2 m/s, and function in pain, touch, pressure, temperature, and post-ganglionic autonomics

Back 21

C, IV

Front 22

these two types of receptors in the somatic sensory system detect light touch, vibration, pressure, and cutaneous tension

Back 22

mechanoreceptors and proprioceptors

Front 23

these two types of receptors in the somatic sensory system detect pain and temperature

Back 23

nociceptors and thermoreceptors

Front 24

these receptors are located in the dermal papillae, the fingers, palms, and toes; they respond to light touch and detect the texture of objects and are low threshold and rapidly adapting

Back 24

Meissner's corpuscles

Front 25

Meissner's corpuscles represent __%of the sensory innervation of the hand

Back 25

40

Front 26

These receptors are in the epidermis, aligned with papillae beneath dermal ridges; they discriminate edges, shapes, and rough texture with light pressure; they have slowly adapting axons and are dense in the fingertips lips, and external genitalia (VERY sensitive)

Back 26

Merkel disks

Front 27

Merkel disks make up __% of the mechanoreceptors in the hand

Back 27

25

Front 28

These receptors are located in the subcutaneous tissue and are made up of a laminar capsule surrounding a single afferent nerve fiber; they detect deep pressure and high frequency and have large receptive fields, and are rapidly adapting and have a low response threshold

Back 28

Pacinian corpuscles

Front 29

Pacinian corpuscles account for __-__% of the innervation of the hand

Back 29

10-15

Front 30

these receptors are long and spindle shaped and are located deep in the skin, ligaments, and tendons; they are particularly sensitive to cutaneous stretch and are slowly adapting

Back 30

Ruffini Corpuscles

Front 31

Ruffini corpuscles account for __% of the receptors in the hand

Back 31

20

Front 32

these receptors are located in every tissue of the body except nervous tissue; they are unspecialized free nervous endings and do not adapt, and pick up pain

Back 32

nociceptors

Front 33

this type of pain usually occurs within 0.1 s after stimulation, and is transmitter over the Adelta fibers; it is an acute, sharp, pricking type of pain

Back 33

First (fast) pain

Front 34

this type of pain occurs 1 second or more after stimulation, and it increases in intensity over time; it is a chronic, burning, aching, throbbing pain and it is transmitted by the unmyelinated C fibers

Back 34

Second (slow) pain

Front 35

these types of nociceptors are associated with unmyelinated C fibers and respond to chemical, thermal, and mechanical stimuli

Back 35

Polymodal

Front 36

these receptors are free nerve endings with receptive fields on the skin surface; they detect temperature changes

Back 36

thermoreceptors

Front 37

cool thermoreceptors are activated by temperatures between __ and __º C, with the highest firing rate being at __

Back 37

5-40, 25

Front 38

warm thermoreceptors are activated by temperatures between __ and __ºC, with the highest firing rate at __

Back 38

29-45, 45

Front 39

this is a phenomenon that occurs when you present a hot stimulus to a cold thermoreceptor, and it perceives it as cold

Back 39

paradoxical cold

Front 40

the sense of limb movement

Back 40

kinesthesia

Front 41

a sense of where limbs are in space

Back 41

limb position sense

Front 42

the two components of proprioception

Back 42

kinesthesia and limb position sense

Front 43

these receptors are small encapsulated sensory receptors that are arranged in parallel with striated muscle fibers; they provide information about the length of the muscle

Back 43

muscle spindles

Front 44

muscle spindles contain these types of sensory afferent fibers

Back 44

IA and II

Front 45

this is an intrafusal fiber that has single file nuclei, and are thin and short

Back 45

nuclear chain fibers

Front 46

this is an intrafusal fiber that has nuclei clustered at the center, and are thicker, and have both static and dynamic types

Back 46

nuclear bag fibers

Front 47

this is the primary, or annulospiral sensory afferent in muscle spindles; they encircle the center of all the intrafusals and are rapidly adapting (fire continuously throughout the stretch then cease once the stretch is finished)

Back 47

IA

Front 48

this is the secondary, or flower spray sensory afferent in muscle spindles; they innervate the end of the chain and the static bag and do not go to the dynamic bag; they are slowly adapting; they respond during stretch but maintain the firing rate after the muscle has stopped moving

Back 48

II

Front 49

these are the spindle efferent fibers that innervate the intrafusal muscle fibers and run in the peripheral nerves along with alpha motor neurons

Back 49

gamma motor neurons

Front 50

these gamma efferents innervate the chain and static bag fibers, and cause them to shorten, increasing the firing rate of IA and II afferents without a change in the extrafusal length

Back 50

static

Front 51

these gamma efferents innervate dynamic bag fibers, and cause the polar regions to contract, resulting in increased polar region resistance to stretch and thus increased sensitivity to velocity changes

Back 51

dynamic

Front 52

this organ is located in the muscle-tendon junction and is distributed among the collagen fibers of the tendon; it responds to muscle tension and force when the tendon pulls on the organ

Back 52

golgi tendon organ

Front 53

each golgi tendon organ is innervated by 1 of which type of afferent nerve?

Back 53

IB

Front 54

the somatosensory system is a __ neuron pathway

Back 54

3

Front 55

the first order neuron of the somatosensory system is located in the __ __ __, and the axon extends into the spinal cord via the dorsal horn to the synapse

Back 55

dorsal root ganglion

Front 56

the second order neuron of the somatosensory system is located in the___; the fibers cross the midline and ascend to the___ and synapse

Back 56

thalamus

Front 57

the third order neuron of the somatosensory system originates in the thalamus and travels to synapse on the __ __ __

Back 57

primary sensory cortex

Front 58

this pathway carries information from the mechanoreceptors about tactile discrimination (light touch), proprioception, and vibration

Back 58

dorsal column medial lemniscus

Front 59

the second order neuron of the dorsal column medial lemniscus pathway synapses at the __ __ __ nucleus of the thalamus

Back 59

ventral posterior lateral

Front 60

the two components of the posterior funiculus, which is made up of the dorsal columns of the spinal cord; the information ascends ipsilaterally into the medulla

Back 60

fasiculus gracilis and fasiculus cuneatus

Front 61

the third order neuron of the dorsal column medial lemniscus pathway terminates on the __ __ of the parietal lobe, in the __ __ cortex

Back 61

postcentral gyrus; primary somatosensory

Front 62

the four Brodmann's areas in the primary somatosensory cortex

Back 62

1,2 3a and 3b

Front 63

the primary somatosensory cortex projects to the __ __ cortex and other regions

Back 63

secondary somatosensory

Front 64

the spinothalamic pathway functions in perception of what three modalities

Back 64

pain, temperature, and crude touch

Front 65

where do the first order neurons of the spinothalamic pathway terminate?

Back 65

the dorsal horn of the spinal cord

Front 66

where do the second order neurons of the spinothalamic pathway terminate?

Back 66

the ventral posterior lateral nucleus of the thalamus

Front 67

where do the third order neurons of the spinothalamic pathway terminate?

Back 67

the somatosensory cortex

Front 68

this pathway/sensory system transmits information about touch and pressure and pain and temperature sensation from the face

Back 68

trigeminal pathway

Front 69

the first order neuron for touch and pressure of the trigeminal system terminates in the __ __

Back 69

principal nucleus

Front 70

the first order neurons for the trigeminal system enter the brainstem at the __

Back 70

pons

Front 71

the first order neurons for pain and temperature in the trigeminal system terminate in the __ __ of the medulla

Back 71

spinal nucleus

Front 72

the second order neurons of the trigeminal pathway terminate where?

Back 72

the ventral posterior medial nucleus of the thalamus

Front 73

the third order neurons of the trigeminal pathway terminate where?

Back 73

cortical neurons in layer IV of the somatosensory cortex

Front 74

this sensory pathway relays unconscious proprioceptive information to the cerebellum; the input comes from the body and provides information relative to the muscles and joints

Back 74

spinocerebellar

Front 75

the first order neurons of the spinocerebellar pathway synapse where?

Back 75

Clarke's column (C8-L3) and the gray matter above and below these levels

Front 76

the second order neurons of the spinocerebellar pathway synapse where?

Back 76

terminate as mossy fibers in the vermis of the cerebellum

Front 77

the second order neurons of the spinocerebellar pathway enter the cerebellum via the __ __ __.

Back 77

inferior cerebellar peduncle

Front 78

these levels of the spinocerebellar pathway provide sensory feedback from the upper extremities during evolving movements

Back 78

C1-C7 (aka spinocuneocerebellar)

Front 79

these levels of the spinocerebellar pathway provide the cerebellum with sensory feedback from the LE and trunk during evolving movements

Back 79

C8-L3 (aka dorsal spinocerebellar)

Front 80

these levels of the spinocerebellar pathway carry internally generated information about central locomotor rhythm

Back 80

L4-S1 (aka ventral spinocerebellar)

Front 81

this is the area of the skin that is innervated by the nerve fibers comprising a dorsal root

Back 81

dermatome

Front 82

Disruption of the medial lemniscal pathway by a lesion would result in loss of what sensations?

Back 82

light touch, proprioception, and vibration

Front 83

hemisection of the spinothalamic tract would result in loss of what sensations?

Back 83

pain, temperature, and crude touch

Front 84

this syndrome occurs when there is a hemisection of the spinal cord that results in contralateral loss of pain, temperature, and crude touch and ipsilateral loss of fine discrimination, active touch, proprioception, and vibration

Back 84

Brown-Sequard syndrome

Front 85

an infarct of the trigeminal pathway would result in a loss of what sensations contralateral to the lesion?

Back 85

pain/temperature and touch/pressure

Front 86

a lesion in the spinocerebellar pathway would lead to what issues?

Back 86

uncoordinated movement and a lack of body awareness (dysmetria and ataxia)

Front 87

a disease that is associated with impaired ability to judge distance or range of movement (overshooting)

Back 87

dysmetria

Front 88

this is a disease that is associated with uncoordinated movement and loss of order of joint motions

Back 88

ataxia

Front 89

the cervical spinal enlargement occurs at these levels

Back 89

C5-T1

Front 90

the lumbar spinal enlargement occurs at these levels

Back 90

L2-S3

Front 91

these are the two branches of spinal nerves

Back 91

ventral and dorsal

Front 92

this branch of the spinal nerve carries the axons of motor neurons

Back 92

ventral

Front 93

this branch of the spinal nerve carries the axons of sensory neurons

Back 93

dorsal

Front 94

this structure contains the cell bodies of the sensory neurons

Back 94

dorsal root ganglion

Front 95

this is a structure where spinal nerves join together to serve a particular area; each contains fibers from more than one spinal nerve

Back 95

plexus

Front 96

nerves that emerge from plexuses are __ nerves

Back 96

peripheral

Front 97

this is a fast, involuntary, unplanned sequence of actions that occur in response to a stimulus

Back 97

reflex

Front 98

this is the pathway followed by nerve impulses to produce a reflex

Back 98

reflex arc

Front 99

these are 1 or more regions of gray matter in the CNS that serve to accept sensory information and send it out via a motor neuron

Back 99

integrating center

Front 100

stretching leads to an increase in this afferent activity

Back 100

Ia

Front 101

the tendon reflex is mediated by which organ located in the muscle tendon?

Back 101

Golgi tendon organ

Front 102

this reflex prevents the muscle from being overloaded; it normalizes muscle tension in the optimal range and enables us to handle delicate objects while exerting a steady grip

Back 102

tendon reflex

Front 103

this is the sensory afferent that is being activated during the tendon reflex

Back 103

IB

Front 104

is the tendon reflex polysynaptic or monosynaptic?

Back 104

polysynaptic

Front 105

this is the phenomenon by which the agonist is excited and the antagonist is inhibited, or vice versa during a reflex

Back 105

reciprocal innervation

Front 106

this reflex is produced by a noxious stimulus, and is polysynaptic; it results in ipsilateral flexor excitation and extensor inhibition; allows for withdrawal of the limb from the noxious stimulus while maintaining balance and posture

Back 106

flexor withdrawal reflex (crossed extension flexor withdrawal reflex)

Front 107

this is a proposed mechanism that is said to control the timing and coordination of complex movement patterns; it is a neural network of interneurons that is capable of generating a rhythmic pattern of motor activity in the absence of movement related sensory input from peripheral receptors

Back 107

central pattern generator

Front 108

the signs of this syndrome include damage to the descending pathways of the brain and brainstem, loss of voluntary movements, spasticity, increased tone, and overactive reflexes, and a positive Babinski's sign

Back 108

upper motor neuron syndrome

Front 109

this syndrome is damage to the cell bodies in the brain stem and spinal cord; muscles become weaker, reflexes are absent, there is decreased muscle tone, paralysis, and areflexia

Back 109

lower motor neuron syndrome

Front 110

this disease presents with a slow degeneration of the neurons controlling movement (both U and L motor neurons); the person has atrophy and weakness, and eventually voluntary movement is lost; may affect the diaphragm

Back 110

amyotrophic lateral sclerosis (ALS)

Front 111

these nociceptor axons conduct at 5-30 m/s and respond to dangerously intense mechanical stimuli or thermal stimuli

Back 111

A delta

Front 112

these nociceptor axons conduct at about 2 m/s and are polymodal; they respond to thermal, mechanical, and chemical stimuli

Back 112

C fibers

Front 113

thermal nociceptors are activated at temperature extremes of greater than __ and less than __ºC

Back 113

45, 5

Front 114

these types of afferent fibers modify the quality and characteristics of pain

Back 114

Aa and Ab (large diameter)

Front 115

this is the excitatory neurotransmitter of Adelta and C afferents that is used by nociceptive afferents to mediate synaptic transmission onto dorsal horn neurons

Back 115

glutamate

Front 116

this substance is released from C afferents; it enhances and prolongs the actions of glutamate and the excitability of the dorsal horn neurons

Back 116

neuropeptides (substance P)

Front 117

this is an altered pain response where there is enhanced sensitivity to stimulation in an area around injured tissue; mildly painful stimuli are perceived as significantly more painful

Back 117

hyperalgesia

Front 118

this is a pain response that occurs when non-painful stimuli are perceived as painful

Back 118

allodynia

Front 119

this is a phenomenon that occurs when previously unresponsive nociceptive endings become responsive (have a lower threshold for activation); it is caused by the release of chemicals that activate or decrease the threshold for nociceptors (histamine, prostaglandin, bradykinin)

Back 119

peripheral sensitization

Front 120

this is a stimulation of sensory neurons that leads to the release of inflammatory mediators (substance P and CGRP) that produces vasodilation, plasma extravasation, and hypersensitivity

Back 120

neurogenic inflammation

Front 121

this phenomenon occurs when there is a hyperexcitability of dorsal horn neurons; occurs when there is repetitive, continuous C fiber firing

Back 121

central sensitization

Front 122

where do the central pain pathways synapse?

Back 122

Rexed's laminae

Front 123

These are 10 layers of spinal gray matter that are arranged from dorsal to ventral and classified according to cellular structure

Back 123

Rexed's laminae

Front 124

this layer of Rexed's laminae contains the posteromarginal nucleus, and has pain and temperature pathways

Back 124

lamina I

Front 125

this layer of Rexed's laminae contains the substantia gelatinosa, and contains pain and temperature pathways that are by interneuron only

Back 125

lamina II

Front 126

this layer of Rexed's laminae contains the substantia gelatinosa and contains pathways for pain by mechanoreceptors

Back 126

lamina III

Front 127

these layers of Rexed's laminae contain the nucleus proprius and contains pain pathways by mechanoreceptors

Back 127

lamina IV, V, VI

Front 128

this layer of Rexed's laminae contains the nucleus dorsalis/Clarke's nucleus and interomedial nucleus; contains 2nd order proprioceptive neurons for LEs and preganglionic sympathetics

Back 128

lamina VII

Front 129

this layer of Rexed's laminae contains motor nuclei and transmits via interneurons

Back 129

lamina VIII

Front 130

this layer of Rexed's laminae contains motor nuclei and transmits via alpha motor neurons

Back 130

lamina IX

Front 131

this layer of rexed's laminae contains neurons surrounding the central canal and contains commissural neurons for pain and temperature sensation

Back 131

X

Front 132

the anterolateral system arises from second order neurons in which laminae?

Back 132

I, IV, V

Front 133

in the gate control theory, these afferent fibers inhibit the firing of neurons in the nociceptive pathway, closing the gate

Back 133

Ab

Front 134

in the gate control theory, these afferent fibers excite spinothalamic neurons but inhibit the firing of lamina II inhibitory interneurons, opening the gate

Back 134

Adelta and C fibers

Front 135

electrical or chemical stimulation of this area in the midbrain can produce relief of pain by activating descending pain modulating pathways that inhibit nociceptive neurons in the spinal cord

Back 135

periaqueductal gray (PAG)

Front 136

this pain phenomenon is when there is a tingling or burning sensation of pain in an amputated body part that occurs when central pain processing circuits are still active in the absence of peripheral inputs

Back 136

phantom pain

Front 137

the cerebral cortex can best be seen in the __ plane of the brain

Back 137

coronal

Front 138

there are __ layers of the cerebral cortex that are primarily named for the shapes of the cell bodies within that layer

Back 138

6

Front 139

this type of stain shows the types of dendrites and axons within the layers of the cortex

Back 139

Golgi stain

Front 140

this type of stain shows the cell bodies within the layers of the cortex

Back 140

Nissi stain

Front 141

this type of stain shows the myelin and axons that are present within the layers of the cortex

Back 141

Weigert stain

Front 142

this layer of the cerebral cortex has granular cell bodies and the axons project horizontally

Back 142

I (molecular layer)

Front 143

this layer of the cerebral cortex has granular cell bodies and the axons project to deeper layers in the same cortical area

Back 143

II (External granular layer)

Front 144

This layer of the cerebral cortex has pyramidal cell bodies and has axons that project to other cortical areas or to the same area in the opposite hemisphere

Back 144

III (external pyramidal layer)

Front 145

this layer of the cerebral cortex has granular cell bodies and has axons that receive the bulk of input from the thalamus

Back 145

IV (internal granular layer)

Front 146

this layer of the cerebral cortex has pyramidal cell bodies with axons that project to subcortical centers

Back 146

V (internal pyramidal layer)

Front 147

this layer of cerebral cortex has fusiform cell bodies and has axons that project to other areas of cortex and to subcortical centers

Back 147

VI (multiform layer)

Front 148

neurons that are in one hemisphere of the cortex can project to the other hemisphere via this structure

Back 148

corpus callosum

Front 149

this is a ridge in the brain

Back 149

gyrus

Front 150

this is a valley in the brain

Back 150

sulcus

Front 151

this is a deep valley in the brain

Back 151

fissure

Front 152

the primary motor cortex is located in this area of the brain

Back 152

precentral gyrus

Front 153

The primary motor cortex is often labeled as Brodmann's area __

Back 153

4

Front 154

the premotor cortex is located in Brodmann's area __

Back 154

6

Front 155

this is an area in the brain that is located anterior to the primary motor cortex and is involved in motor planning

Back 155

premotor cortex

Front 156

these are the four components of the premotor cortex

Back 156

Premotor Dorsal (PMd), Premotor ventral (PMv), Supplementary Motor Area (SMA), and the Cingulate Motor Area (CMA)

Front 157

the function of this area of the brain is to execute voluntary movement through activation of the muscle via spinal motoneurons

Back 157

primary motor cortex

Front 158

the function of this section of the premotor cortex is to plan "where" to move; gives the body information about the location of an object

Back 158

Premotor Dorsal

Front 159

the function of this section of the premotor cortex is to plan "what" to move; gives the body information about the properties of the object

Back 159

Premotor Ventral

Front 160

this area of the premotor cortex is involved in sequence learning (series activation of movement) and imagined movements "motor imagery"

Back 160

Supplementary motor area

Front 161

this area of the premotor cortex is located on the very medial portion of the cortex, and it's function is still widely unknown, however it has been proposed that it is involved in planning voluntary movements with respect to reward

Back 161

Cingulate motor area

Front 162

this concept states that multiple pieces of information from multiple cortical neurons come together to activate a single spinal motoneuron

Back 162

convergence

Front 163

this concept states that a single piece of information is spread to multiple spinal motoneurons

Back 163

divergence

Front 164

this idea states that the use, or non-use, of a muscle can change its cortical representation (change in the somatotopic map)

Back 164

neuroplasticity

Front 165

this descending motor pathway is the most direct pathway from the cortex to the spinal motoneurons

Back 165

the corticospinal tract

Front 166

From where does the corticospinal tract originate?

Back 166

many areas in the frontal and parietal lobes

Front 167

about __% of the axons in the corticospinal tract come from the primary motor cortex

Back 167

30

Front 168

about __% of the axons in the corticospinal tract come from the non-primary motor areas (SMA, PM, CMA)

Back 168

30

Front 169

about __% of the axons in the corticospinal tract come from the parietal lobe (Brodmann's areas 1,2,3,5 and 7)

Back 169

40

Front 170

Corticospinal tract axons arise from the large and small pyramid-shaped cell bodies in cortical layer __

Back 170

V

Front 171

The axons of the corticospinal pathway pass through the __ __ after leaving the cortex

Back 171

corona radiata

Front 172

the axons of the corticospinal tract enter the brain where?

Back 172

the internal capsule

Front 173

within the internal capsule, the corticospinal neurons are located within the __ limb

Back 173

posterior

Front 174

the axons in the corticospinal tract that come from the nonprimary motor areas pass through the __ and the __ 1/3 of the internal capsule

Back 174

genu, anterior

Front 175

the axons in the corticospinal tract that come from the primary motor cortex pass through the __ 1/3 of the internal capsule

Back 175

middle

Front 176

the axons in the corticospinal tract that come from the parietal areas pass just __ to the M1 axons in the internal capsule

Back 176

posterior

Front 177

As the axons of the corticospinal tract descend through the internal capsule, they shift posteriorly and pass below the __

Back 177

thalamus

Front 178

After passing below the thalamus, the axons of the corticospinal pathway descend through the middle 1/3 of the __ __ of the midbrain

Back 178

cerebral peduncle

Front 179

After descending through the cerebral peduncle, the axons of the corticospinal pathway go to the __, where they pass around nuclei

Back 179

pons

Front 180

After they pass around nuclei in the pons, the axons of the cerebrospinal tract enter the __ to form pyramids

Back 180

medulla

Front 181

At this junction, the majority of the fibers of the corticospinal tract cross the midline (decussate) to become the lateral corticospinal tract

Back 181

spinomedullary junction

Front 182

At the spinomedullary junction, about __% of the corticospinal axons cross the midline to become the lateral CST

Back 182

85

Front 183

The remaining axons that did not cross at the spinomedullary junction continue to descend uncrossed as the __ corticospinal tract

Back 183

ventral

Front 184

axons traveling in the __ corticospinal tract tend to synapse on motoneurons and interneurons involved in the control of more distal musculature

Back 184

lateral

Front 185

axons traveling in the __ corticospinal tract tend to synapse on motoneurons and interneurons involved in the control of more proximal limb muscles and axial musculature

Back 185

ventral

Front 186

Less than __% of the axons in the corticospinal tract recross the midline in the spinal cord and terminate on the ventral horn ipsilateral to their origin

Back 186

10%

Front 187

the first order neurons in the vestibulospinal tract come from the __ __ in cranial nerve __

Back 187

vestibular ganglion, VII

Front 188

the first order neurons in the vestibulospinal tract enter the brainstem at the __ __ junction

Back 188

lateral pontomedullary

Front 189

the first order neurons in the vestibulospinal tract synapse on __ vestibular nuclei after entering the brainstem at the lateral pontomedullary junction

Back 189

4 (superior, lateral, inferior, and medial)

Front 190

some of the 1st order fibers of the vestibulospinal tract also go straight to the __ of the brain

Back 190

cerebellum

Front 191

the second order neurons from the lateral vestibular ganglion form the __ __ tract

Back 191

lateral vestibulospinal

Front 192

the second order neurons from the medial vestibular ganglion form the __ __ tract

Back 192

medial vestibulospinal

Front 193

the __ vestibulospinal tract prefers axial and proximal limb motorneuron pools

Back 193

lateral

Front 194

the __ vestibulospinal tract controls axial muscles related to head and neck movements

Back 194

medial

Front 195

the origin of the reticulospinal tract is the __ __

Back 195

reticular formation

Front 196

The most important source of input to the reticular formation are these areas

Back 196

the bilateral motor areas (primary motor cortex, premotor cortex, and supplementary motor area)

Front 197

the reticulospinal tract in man exists as a scattered bundle of fibers, terminating primarily in the __ portion of the spinal gray matter at or above the __ enlargement

Back 197

venteromedial, cervical

Front 198

this tract does motor control that is exerted chiefly over axial and proximal limb musculature to assist with postural control and orientation

Back 198

reticulospinal tract

Front 199

the origin of the rubrospinal tract is in the __ __ of the midbrain

Back 199

red nucleus

Front 200

the red nucleus of the midbrain receives input from the __ motor cortex

Back 200

ipsilateral

Front 201

the axons of the rubrospinal tract cross immediately to the opposite side in the __ __ __

Back 201

anterior tegmental decussation

Front 202

the axons of the rubrospinal tract that have crossed descend in the __ column of the spinal cord

Back 202

lateral

Front 203

the axons of the rubrospinal tract terminate in the dorsal and lateral parts of the __ __ of the spinal cord

Back 203

intermediate zone

Front 204

the primary somatosensory cortex contains these Brodmann's areas

Back 204

1, 2, 3a and 3b

Front 205

the primary somatosensory cortex is known by this symbol

Back 205

S1

Front 206

the secondary somatosensory cortex is known by this symbol

Back 206

S2

Front 207

this phenomenon explains that some areas of the body take up much more territory in the cortex than you would think based on their size (more receptor density)

Back 207

cortical magnification

Front 208

It is easier to measure plastic changes in __ because it is very strictly/intricately arranged somatotopically

Back 208

S1

Front 209

the primary sensory cortex is located in the __ gyrus of the parietal lobe

Back 209

postcentral

Front 210

__ __ at all levels of sensory pathways allows for accurate stimulus localization; it is known as the capacity of an excited neuron to reduce the activity of its neighbors

Back 210

lateral inhibition

Front 211

__ neurons provide information needed to precisely control hand and finger movements (e.g. grasping)

Back 211

S1

Front 212

these types of neurons in the sensory system respond to movement in all directions

Back 212

motion-sensitive

Front 213

these types of neurons in the sensory system respond to movement most in one direction

Back 213

direction-sensitive

Front 214

these types of neurons in the sensory system respond more to movement along one axis than to movement along another axis

Back 214

orientation-sensitive

Front 215

this is the capability of being molded; the capacity of representation (maps) in the central nervous system are able to be changed as a result of alterations in inputs and direct damage

Back 215

plasticity

Front 216

These are four ways to measure motor plasticity

Back 216

ICMS, PET scan, TMS, and fMRI

Front 217

this procedure is performed when the skull is opened and electrodes are inserted into a gridlike pattern; current is sent through the electrodes and which body part moves is observed

Back 217

intracortical microstimulation (ICMS)

Front 218

this procedure to measure motor mapping is when a person is asked to perform a task, and it is seen which areas of the brain have more blood flow to them during and after the task is performed

Back 218

fMRI

Front 219

there is a general trend for somatotopy with the trunk more __ and the jaw/face more __

Back 219

medial, lateral

Front 220

in this type of motor mapping technology, a device is put onto the outside of the head and a magnetic pulse induces brain current, which increases the EMG activity of a muscle (where? to what magnitude?)

Back 220

transcranial magnetic stimulation (TMS)

Front 221

motor __, not use, is associated with an M1 plasticity

Back 221

learning

Front 222

this is a large, functionally diverse set of nuclear structures that lie deep within the cerebral hemispheres and influence movement by acting upon/regulating upper motor neurons

Back 222

basal ganglia

Front 223

this is the relay center for the CNS

Back 223

thalamus

Front 224

these are the 6 nuclei that comprise the basal ganglia

Back 224

Striatum, subthalamic nucleus (STN), GPi, SNr, GPe, and SNc

Front 225

these are the two components of the striatum

Back 225

caudate and putamen

Front 226

this is the largest input to the basal ganglia

Back 226

the cerebral cortex

Front 227

cortical input to the basal ganglia is excitatory, and uses __ as its neurotransmitter

Back 227

glutamate

Front 228

the subthalamic nucleus receives __ input from the frontal cortex

Back 228

excitatory

Front 229

the striatum receives __ input from the thalamus and brainstem

Back 229

excitatory

Front 230

the striatum receives __ input from the brainstem and local interneurons

Back 230

inhibitory

Front 231

these two areas project to the posterior putamen

Back 231

somatosensory and motor cortices

Front 232

this area projects to the anterior caudate

Back 232

prefrontal cortex

Front 233

this area of the striatum is associated with movements of the body

Back 233

putamen

Front 234

this area of the striatum is associated with movements of the eyes

Back 234

caudate

Front 235

in the striatum, the cortical inputs terminate on these types of neurons

Back 235

medium spiny neurons (MSNs)

Front 236

the medium spiny neurons utilize __ as their neurotransmitter, which cause them to send inhibitory inputs to both the GP and the SN

Back 236

GABA

Front 237

these neurons send inhibitory output to structures outside of the basal ganglia, most importantly the ventral anterior and lateral nuclei of the thalamus

Back 237

GPi

Front 238

The GPi receives inhibitory input from these two structures

Back 238

Striatum and GPe

Front 239

the GPi receives excitatory input from this structure

Back 239

STN

Front 240

the SNr receives inhibitory input from these structures

Back 240

striatum, GPe

Front 241

the SNr receives excitatory input from this structure

Back 241

STN

Front 242

these neurons send inhibitory output to structures mainly outside the basal ganglia, namely the superior colliculus and frontal eye fields, as well as ventral anterior and lateral nuclei of the thalamus

Back 242

SNr

Front 243

the GPe receives inhibitory projections from this nucleus

Back 243

striatum

Front 244

this nucleus sends inhibitory projections to both the SNr and the GPi

Back 244

GPe

Front 245

these nuclei are large dopamine containing cells, and send projections back to the striatum that are dependent upon the type of dopamine receptor located on the striatal neuron

Back 245

SNc

Front 246

the SNc receives inhibitory projections from this area

Back 246

striatum

Front 247

the GPi contains __ dopamine receptors

Back 247

D1

Front 248

the GPe contains __ dopamine receptors

Back 248

D2

Front 249

the direct pathway functions via the medium spiny neurons that contain __ dopamine receptors

Back 249

D1

Front 250

the indirect pathway functions via the medium spiny neurons that contain __ dopamine receptors

Back 250

D2

Front 251

this pathway inhibits the tonically active inhibitory firing of the Gpi neurons, resulting in upper motor neurons being released from their tonic inhibition

Back 251

direct pathway

Front 252

this pathway increases the tonic firing of the GPi neurons, thus increasing the inhibitory output from the basal ganglia and inhibiting the upper motor neurons (surround inhibition of competing movements)

Back 252

indirect pathway

Front 253

the net effect of this neurotransmitter is to allow movement to take place more easily

Back 253

dopamine

Front 254

these disorders occur when there is an overactive indirect pathway that increases inhibitory output from the BG, resulting in excessive inhibition of upper motor neurons; due primarily to increased drive from the STN

Back 254

Hypokinetic disorders

Front 255

these disorders result from an underactive indirect pathway, which causes reduced inhibitory output of the BG and unwanted excitation of the upper motor neurons (uncontrollable movements)

Back 255

Hyperkinetic disorders

Front 256

types of hypokinetic disorders

Back 256

Akinesia, bradykinesia, rigidity, tremor at rest

Front 257

types of hyperkinetic disorders

Back 257

Athetosis, Ballismus, chorea, dystonia, dyskinesias, Huntington's disease

Front 258

this is a disease that is predominantly manifested in the 4th or 5th decade, and the prominent symptom is chorea; it includes other hyperkinetic symptoms and there are emotional and cognitive changes as well

Back 258

Huntington's disease

Front 259

this is a hyperkinetic symptom that is manifested in rapid, jerky ballistic movements (dancelike)

Back 259

chorea

Front 260

this disease is characterized by violent, involuntary movements of the limbs due to lesion of the STN; the movements are due to discharges of the upper motor neurons that are now less tonically inhibited

Back 260

hemiballismus

Front 261

hemiballismus manifests itself in the side of the body __ to the lesion

Back 261

contralateral

Front 262

this disease is characterized by sustained muscle contractions that cause twisting, repetitive movements and abnormal postures

Back 262

dystonia

Front 263

This disease has many hypokinetic symptoms (tremor, rigidity, etc) that results in postural instability, a flexed forward posture, mask-like face, shuffling gait, and monotonous speech

Back 263

Parkinson's disease

Front 264

This disease is caused by loss of SNc neurons, causing loss of dopamine, and the BG output becomes abnormally inhibitory

Back 264

Parkinson's disease

Front 265

These are all of the sensory pathways that ascend from the periphery to the CNS

Back 265

(1) Dorsal column medial lemniscus
(2) Spinothalamic
(3) Trigeminal
(4) Spinocerebellar

Front 266

These are all of the motor pathways that descend from the CNS to the periphery

Back 266

(1) Corticospinal
(2) Reticulospinal
(3) Rubrospinal
(4) Vestibulospinal

Front 267

what are the two types of rapidly adapting sensory receptors?

Back 267

Pacinian corpuscles and Meisner's corpuscles

Front 268

what are the two types of slowly adapting sensory receptors?

Back 268

Merkel discs and Ruffini corpuscles

Front 269

Brodmann's area 3a in the primary somatosensory cortex are associated with what proprioceptive structure?

Back 269

muscle spindles

Front 270

Brodmann's areas 3b and 1 in the primary somatosensory cortex are associated with what sensory receptors?

Back 270

cutaneous

Front 271

Brodmann's area 2 in the primary somatosensory cortex is associated with what sensory receptors?

Back 271

deeper receptors within joints and muscles

Front 272

which layers of Rexed's laminae are located in the dorsal horn of the spinal cord?

Back 272

I-VI

Front 273

what are the two nuclei of the basal ganglia that receive input from structures outside the BG?

Back 273

Straitum and STN

Front 274

what are the two nuclei of the basal ganglia that send output to structures outside the BG?

Back 274

GPi and SNr

Front 275

what are the two nuclei of the basal ganglia that are intrinsic (all projections are inside the BG)?

Back 275

GPe and SNc

Front 276

During deep brain stimulation, which brain region would be targeted in order to reduce tremors?

Back 276

thalamus

Front 277

During deep brain stimulation, which brain structure would be targeted in order to reduce dyskinesia and choreic movements?

Back 277

GPi

Front 278

During deep brain stimulation, which brain region would be targeted in order to reduce bradykinesia and axial motor symptoms?

Back 278

STN