Anatomy Ch. 7 Nervous System

Front 1

I. Olfactory

Back 1

Purely sensory; carries impulses for the sense of smell

Front 2

II. Optic

Back 2

Purely sensory; carries impulses for vision

Front 3

III. Oculomotor

Back 3

supplies motor fibers to our of the six muscles that direct the eyelid; and to the internal eye muscles controlling lese shape and pupil size

Front 4

IV. Trochlear

Back 4

Supplies motor fibers for one external eye muscle (superior oblique)

Front 5

V. Trigeminal

Back 5

conducts sensory impulses from the skin of the ace and mucosa of the nose and mouth; also contains motor fibers that activate the chewing muscles

Front 6

VI. Abducens

Back 6

Supplies motor fibers to the lateral rectus muscle, which rolls the eye laterally

Front 7

VII. Facial

Back 7

Activates the muscles of the facial expression and the lacrimal and salivary glands; carries sensory impulses from the taste buds of anterior tongue

Front 8

VII. Vestibulocochlear

Back 8

Purely sensory; vestibular branch transmits impulses for the sense of balance, and cochlear branch transmits impulses for the sense of hearing

Front 9

IX. Glossopharyngeal

Back 9

Supplies motor fibers to the pharynx (throat) that promote swallowing and saliva production; carries sensory impulses from taste buds of the posterior tongue and from pressure receptors of that carotid artery

Front 10

X. Vagus

Back 10

Fibers carry sensory impulses from and motor impulses to the pharynx, larynx, and the abdominal and thoracic viscera; most motor fibers are parasympathetic fibers that promote digestive activity and help regulate heart activity

Front 11

X1. Accessory

Back 11

Mostly motor fibers that activate the sternocleidomastoid and trapezius muscles

Front 12

XII. Hypoglossal

Back 12

Motor fibers control tongue movements; sensory fibers cary impulses rom the tongue

Front 13

Central Nervous System (CNS)

Back 13

consists of the brain and spinal cord, which occupy the dorsal body cavity and act as the integrating and command centers of the nervous system. Interprets incoming sensory info. and issues instructions based on past experience and current conditions

Front 14

Peripheral Nervous System (PNS)

Back 14

part of the nervous system outside the CNS. Consists mainly of the nerves that extend rom the brain and spinal cord.

Front 15

Spinal Nerves

Back 15

carry impulses from and to the spinal

Front 16

cranial nerves

Back 16

carry impulses to and from the brain

Front 17

sensory (afferent) division

Back 17

consists of nerve fibers that convey impulses to the cns from sensory receptors

Front 18

motor (efferent) division

Back 18

carries impulses from the CNS to effector organs, the muscles and glands. These impulses actgivate muscles and glands; they effect a motor response

Front 19

somatic nervous system

Back 19

allows us to consciously, or voluntarily, control our skeletal muscles. Also known as voluntary nervous system

Front 20

autonomic nervous system (ANS)

Back 20

regulates events that are automatic, or involuntary, such as the activity of smooth and cardiac muscles and glands. Also called the involuntary nervous system.

Front 21

neuroglia

Back 21

nerve glue. gerally suypports, insulates, and protects neurons. (Glia)

Front 22

glia

Back 22

Neuroglia. Consists of Astrocytes, microglia, ependymal cells, and oligodendrocytes

Front 23

astrocytes

Back 23

star shaped cells that account for nearly half of neural tissue. Cling to neurons, bracing them and anchoring them to the nutrient supply lines (the blood capillaries)

Front 24

microglia

Back 24

spiderlike phagocytes that dispose of debris, including dead brain cells and bacteria

Front 25

ependymal cells

Back 25

line the cavities of the brain and the spinal cord. Helps to circulate the cerebrospinal fluid.

Front 26

oligodendrocytes

Back 26

glia that wrap their flat extensions tightly around the nerve fiers, producing myelin sheaths

Front 27

myelin sheaths

Back 27

fatty insulating coverings

Front 28

schwann cells

Back 28

form myelin sheaths around nerve fibers that are found in the PNS

Front 29

satellite cells

Back 29

act as protective, cushioning cells

Front 30

Nissl substance

Back 30

the rough ER in neurons

Front 31

neurofibrils

Back 31

important in maintaining cell shape

Front 32

dendrites

Back 32

neuron processes that convey incoming messages toward the cell body

Front 33

axons

Back 33

generate nerve impulses and typically conduct them away from the cell body

Front 34

axon terminals

Back 34

contain hundreds of tiny vesicles, or membranous sacs, that contain chemicals called neurotransmitters

Front 35

synaptic cleft

Back 35

a gap that separates each axonal terminal from the next neuron

Front 36

white matter

Back 36

consists of dense collections o myelinated fibers

Front 37

gray matter

Back 37

contains mostly unmyelinated fibers and cell bodies

Front 38

seonsory (afferent) neurons

Back 38

neurons carrying impulses rom sensory receptors to the CNS

Front 39

motor (efferent) neureons

Back 39

neurons carrying impulses from the CNS to the viscera and/or muscles and glands. Their cell bodies are always located int he CNS

Front 40

association neurons (interneurons)

Back 40

connect the motor and sensory neurons in neural pathways. Cell bodies always located in the CNS

Front 41

multipolar neuron

Back 41

if there are several processes extending from the cell body, the neuron is multipolar

Front 42

bipolar neurons

Back 42

neurons with two processes-- an axon and a dendrite. Rare in adults, found only in some special sense organs (eye, ear) where they act as sensory receptor cells.

Front 43

unipolar neurons

Back 43

have a single process emerging from the cell body however it is very short and divides almost imediately into proximal (central) and distal (peripheral) fibers.

Front 44

irritability

Back 44

the ability to respond to a stimulus and convert it into a nerve impulse

Front 45

conductivity

Back 45

the ability to transmit the impulse to other neurons, muscles, or glands.

Front 46

polarized

Back 46

there are fewer positive ions sitting on the inner face of the neuron's plasma membrane than there are on its outer fface in the tissue fluid that surrounds it.

Front 47

depolarization

Back 47

the inward rush of sodium ions which changes the polarity of the neuron's membrane

Front 48

action potential

Back 48

an electrical event occurring when a stimulus of suficient intensity is applied to a neuron or muscle cell, allowing sodium ions to move into the cell and reverse the polarity

Front 49

repolarization

Back 49

the outflow of positive ions from tthe cell which restores the electrical conditions at the membrane to the polarized, or resting, state

Front 50

cerebral hemispheres

Back 50

most superior part of the brain and together are a good deal larger than the other three brain regions combined. Enclose and obscure most of the brain stem