Nervous System

Front 1

Nervous System
(2 types)

Back 1

1. CNS (Central Nervous System)

2. PNS (Peripheral Nervous System)

Front 2

CNS Anatomical Locations

Back 2

- Brain
1. Cerebrum
2. Cerebellum
3. Brainstem
- Spinal Cord
1. Cervical Enlargement
2. Thoracolumbar Division
3. Sacral Enlargement

Front 3

PNS Anatomical Locations

Back 3

- Cranial Nerves
- Spinal Nerves
- Ganglia

Front 4

Peripheral Nervous System
(PNS)

Back 4

A. Afferent (Sensory) Fibers
B. Efferent (Motor) Fibers
C. Interneuron

Front 5

PNS:
Efferent (Motor) Fibers

Back 5

Efferent (Motor) Fibers
1. Somatic Fibers
a.) NO synapse after CNS
b.) Innervate SKELETAL
muscle only!
c.) Excite skeletal muscle
2. Autonomic Fibers
a.) Synapse after leaving
the CNS.
b.) Innervate smooth and
cardiac muscle.
c.) Excite or inhibit
effector cells.
~> Sympathetic
~> Parasympathetic

Front 6

Two Autonomic Divisions

Back 6

1. Sympathetic Division (ALERT)
- Thoracolumbar Origin
- Adrenergic fibers secrete
norepinephrine."adrenaline"
- "Fight or Flight" response

2. Parasympathetic Division (REST)
- Cranial-Sacral Origin
- Cholinergic Fibers
secrete acetylcholine.

Front 7

CNS Summary:

Back 7

1. Fibers arranged as Tracts.
2. Nerve Cell bodies form a Nucleus.
3. Oligodendrocytes secrete myelin.

Front 8

PNS Summary:

Back 8

1. Fibers arranged as Nerves.
2. Nerve Cell Bodies for a Ganglion.
3. Schwann Cells secrete Myelin.

Front 9

Sensory (Afferent) Division

Back 9

- transmits information from periphery to the CNS.
- Contains receptors.
- SOMATIC SENSORY and VISCERAL SENSORY

Front 10

Motor (Efferent) Division

Back 10

- Transmits information from CNS to the rest of the body.
- Sends motor information to effectors.
- SOMATIC MOTOR and AUTONOMIC MOTOR

Front 11

Somatic Sensory:

Back 11

- receives sensory information from skin, fascia, joints, skeletal muscles, special senses.

Front 12

Visceral Sensory:

Back 12

- Receives sensory information from viscera

Front 13

Somatic Motor:

Back 13

- "Voluntary" nervous system: innervates skeletal muscle.

Front 14

Autonomic Motor

Back 14

- "Involuntary" nervous system: innervates cardac muscle, smooth muscle, glands.

Front 15

Characteristics of Nerve Fibers:

Back 15

1. "All or None" response
(Neuron voltage is Constant!)
2. Nerves are composed of many Neurons. (Nerve voltage is Variable!)
3. Nerve voltage depends on how many neurons fire at one time.
Nerves conduct higher voltages by:
a. increasing the number of neurons firing in a second = spatial summation.
b. Firing the same neurons many times per second = temporal summation.

Front 16

Neural Integration:
How a neuron determines when to fire.

Back 16

Clue: there are 2 types of neurotransmitters.
-excitatory
-inhibitory

Front 17

Neural Integration:
How a neuron determines when to fire.
EXCITATORY

Back 17

Excitatory Neurotransmitter is released onto the Post-Synaptic Fiber.
1. Increases the permeability to Sodium Ions. (more apt to fire)
2. Generates an excitatory Post-Synaptic Potential (EPSP)
3. The Post-Synaptic Fiber Fires.

Front 18

Neural Integration:
How a neuron determines when to fire.
INHIBITORY

Back 18

Inhibitory Neurotransmitter is released onto the Post-Synaptic Fiber.
1. Decreases the permeablity to Sodium Ions. (Less apt to fire)
2. Generates an Inhibitory Post-Synaptic Potential (IPSP)
3. THe Post-Synaptic Fiber does not Fire.
-Several EPSPs and IPSPs are generated at the same time.

Front 19

What are the functions of Neuroglia?

Back 19

- Supports, protect and nourish neurons.

Front 20

Myelin is formed differently in the CNS and PNS.
Do these differences affect the ability of neurons to repair?

Back 20

YES.

Front 21

____ Neurons are expected to repair damaged axons.

Back 21

PNS.

Front 22

PNS Nerves are similar in structure to ______ muscle.

Back 22

Skeletal.

Front 23

Chemical Synapses release two types of ________.

Back 23

Neurotransmitters.

Front 24

Neural ________ involves a neuron summing the input from all firing _______ responding accordingly.

Back 24

Integration; neurons.

Front 25

Neuronal Circuits

Back 25

1. Converging (ex. Salivary Nucleus of Brain.
2. Diverging (ex. Synergistic muscle control by motor neurons.
3. Reverberating (ex. Breathing control by respiratory neurons.)
4. Parallel after-discharge (ex. Complex thought... problem solving)

Front 26

What does the Choroid Plexus produce?

Back 26

CSF (Cerebral Spinal Fluid)

Front 27

What absorbs CSF at the top of the brain?

Back 27

Arachnoid Villi

Front 28

CSF (Cerebro-Spinal Fluid) Summary:

Back 28

1. It is a chemically enhanced capillary filtrate.
2. Produced by the Choroid Plexuses in each ventricle.
3. Absorbed by the Arachnoid Villi on top of the Brain.
4. Acts as a Hydraulic Buffer to protect the outer CNS.
5. Provides an internal support as a Hydrostatic Skeleton.

Front 29

Reflexes:

Back 29

1. The simplest behavior.
2. Selected for Survival Value.
3. Operate below the level of the cerebral Cortex. (sub-cortical= Below the level of consciousness)
4. Provide for Rapid Responses to Critical Situations.
(faster than going to the brain and back)
5. Can be simple or complex in design and operation.
(one synapse to many synapses)

Front 30

Basic components of a Reflex Arc:

Back 30

1. Receptor
2. Sensory Neuron
3. Motor Neuron.
4. Effector.
NOTE: zero to several interneurons may be added.

Front 31

Monosynaptic Reflex:

Back 31

Direct communication between sensory and motor neuron.
(ex. Knee-jerk reflex)

Front 32

Disynaptic Reflex:

Back 32

Interneurons facilitates sensory-motor communications.
(ex. burn withdrawal reflex.)

Front 33

The lower CNS is organized to:

Back 33

1. receive sensory information from the PNS and relay it to other parts of the CNS>
2. receive motor information from the CNS and relay it to the PNS.
3. perform Reflex Arcs to quickly respond to sensory input from the PNS.

Front 34

The ______ support the neurons of the CNS>

Back 34

Meninges.

Front 35

________ performs several supportive ______ for the neurons of the CNS.

Back 35

CSF; functions.

Front 36

Medulla Oblongata

Back 36

A. Ascending and Descending Tracts.
B. Descending Tracts are called Pyramids.
-Decussation of Pyramids occur.
C. Vital Reflex Centers
1. Cardiac Control Centers
2. Vasomotor Cntrol Centers.
3. Respiratory Rhythmicity Centers (inhale, exhale)
-Coughing, sneezing, swallowing, vomiting (autonomic controls)
D. Reticular Formation
-Comprises the Reticular Activating System.
-Orients the Higher Brain.

Front 37

Pons

Back 37

A. Dorsal and Ventral Fiber Tracts.
1. Drasal Tracts run in the longitudinal plane.
-connect the Medulla to the Cerebrum.
2. Vental Tracts run in the transverse plane.
- Connect the Medulla to the Cerebellum.
3. Acts as a relay between the lower and higher CNS.
4. Respiratory Cntrol Centers.
- Pneumtaxicand apneustic centers.
- influence the Medullary Respiratory Centers.

Front 38

Cerebellum

Back 38

A. Commutator
1. Smooths out sporadic motor impulses from the Cerebrum.
2. Cordinates impulses for motor control.
3. eliminates undesired motor impulses.
B. Proprioception center (controls Balance and Posture)
a. Superior Cerebellar Peduncles.
- Sends impulses from the Cerebellum to the mid-brain then down to the lower CNS. (controlling output)
b. Middle Cerebellar Peduncles.
- Brings impulses concerning the desired position of bdy parts frm the Cerebrum. (desired positions)
c. inferior Cerebellar Peduncles.
-brings impulses concerning the actual position of the body from the lower CNS (actual position)
C. Stores memory for semi-voluntary mvements.
-memory traces of specific learned balance movements.

Front 39

Mid-Brain

Back 39

A. Cerebral Peduncles
1. Ascending and Descending tracts.
2. Relay between lwer and higher CNS.
B. Cerebral Aqueduct.
1. Connects 3rd and 4th Ventricles.
2. Carries CSF
C. Corpora Quadrigemina
- Reflex centers for Special Sensory organs.
a. Superis Colliculus - Eye reflexes.
b. Inferior Colliculus - Ear reflexes.
D. Pineal Body
a. Endocrine Gland that secretes Melatonin.
b. Regulator of Biorythms.

Front 40

Cerebrum

Back 40

-Center of Higher Thought Processes.
-Receives & Interprets Sensory Impulses.
-Initiates Motor Responses.
-Monitors & Coordinates Body Functions.
A. Cerebral Cortex - specialized areas w/ discrete functions.
B. Basal Ganglia or Nuclei (extrapyramidal Tracts)
1. Caudate Nucleus, Lentiform Nucleus and the Claustrum.
2. Eliminates Undesired Mtor Impuses (role of Dopamine)
C. Thalamus
1. Major Relay Center between Cerebral Cortex and lower CNS.
2. Twenty separate Nuclei carry sensory impulses to the cortex.
3. Motor impulses are relayed to lower CNS.
D. Hypthalamus
1. Major Mnitring Unit f CNS.
2. Regulates Body Functins through negative feedback
3. Maintains homeostasis
E. Limbic System
1. Composed of many subcortical nuclei.
2. Center of Strong Emotins.
3. "Pleasure and Punishment" centers.
4. Neural chassis that supprts the cerebral cortex.

Front 41

Cerebrum:
Cerebral Cortex

Back 41

1. Frontal Association Area - logic and higher though.
2. Premotor Area (extrapyramidal tracts) = Frontal Cortex.
-choreographs voluntary motor commands.
-"soft wired" programmable, can rewire after damage.
3. Primary Motor Area (pyramidal tracts) = pre-central gyrus
-Issues Voluntary Motor Commands
-"hard-wired" = any damage i permanent.
4. Primary Sensory Area = Post-central Gyrus
- receives general sensory impulses
5. Somatic (Somesthetic) Assciatin Area -Parietal Cortex
- interprets general sensory impulses.
6. Primary Visual Area = Occipital Cortex
-receives visual impulses
7.Visual Assocatin Areas
-interprets visual impulses.
8. Primary Auditory Areas = Temporal Cortex
-receives auditory impulses.
9. Auditory Assocation Areas
-interprets auditry impulses
10. Broca Speech Area
- Motor control of Speech
11. Wernicke's Speech Area
- Selection of words for speech

Front 42

The _______ acts as a Commutator and center of _______.

Back 42

Cerebellum; Proprioception.

Front 43

The ______ Nuclei perfrm a number of complex functins in supprt of the activities of the Cerebral _______.

Back 43

Cerebral; Cortex

Front 44

Meningitis:

Back 44

inflammation of the meninges. Caused by either Viral or Bacterial infection. Mortality rate varies from 1%-50%! Often strikes young adult under stress.

Front 45

Poliomyelitis:

Back 45

Progressive paralysis due to the destruction of Motor Neurons of the Anterior Gray horn by Polio Virus.

Front 46

Encephalitis:

Back 46

Inflammation of the Brain Tissues. Caused by either Bacterial or Viral infections

Front 47

Multiple Sclerosis:

Back 47

A disease characterized by demylination of CNS neurons and replacement by connective tissue "plaques" resulting in the inability to conduct impulses. Thought to be an autoimmune disorder. The first attack is between 30-40 years old and is about 50% higher women than in men.

Front 48

Cerebral Palsy:

Back 48

A chronic muscular disorder that begins in infancy or childhood resulting from damage t the extrapyramidal neurons during embryonic development or labor.

Front 49

Parkinson's disease:

Back 49

produces erratic and unwanted skeletal muscle contractions. Cx by the inability f the cells of the Substantia Nigra (cerebral nuclei) to secrete the inhibitory neurotransmitter Dopamine. Tx w/ the injection f L-Dpa which promotes neural secretions of Dopamine.

Front 50

Peripheral Nervous System:
SOMATIC SYSTEM

Back 50

1. Fibers do not synapse after leaving CNS.
2. Nerves innervate skeletal muscle & skin.
3. Excite effector cells.
4. Secretes acetylcholine as neurotransmitter.

Front 51

Peripheral Nervous System:
AUTONOMIC SYSTEM

Back 51

1. Fibers synapse after leaving CNS.
2. Nerves innervate smooth & cardiac muscle.
3. Can excite or inhibit effector cells.
4. Secrete either acetylcholine or norpinephrine as neurotransmitter.

Front 52

Parasympathetic

Back 52

*Acetylcholine
1. LONG Preganglionic fibers.
2. SHORT Postganglionic fibers.
3. Ganglia on or near Viscera.
4. Cranial-Sacral Origin
5. Acetylcholine released onto Effector.
6. Relaxes the body

Front 53

Sympathetic

Back 53

*Norepinephrine
1. SHORT Preganglinic fibers.
2. LONG Postganglinic fibers.
3. Ganglia near Vertebral Column.
4. Throacolumbar Origin.
5. Norepinephrine released onto Effector.
6. Alerts the Body

Front 54

The PNS is separated into _______ and _______ systems.

Back 54

Somatic; autonomic.

Front 55

Somatic fibers innervate ______ muscle and skin.

Back 55

Skeletal.

Front 56

Autonomic fibers innervate ________ organs.

Back 56

Visceral.

Front 57

How many neurotransmitters are released in the PNS?

Back 57

2

Front 58

Acetylcholine is released by all PNS fibers except?

Back 58

Sympathetic Post-Ganglionic Fibers

Front 59

What promotes a "fight or flight" response?

Back 59

Sympathetic division.

Front 60

What promotes a "rest" state?

Back 60

Parasympathetic