nervous system structures, functions, & word parts

central nervous system

brain and spinal cord

function of central nervous system

receive and process information and to regulate body activity

peripheral nervous system

12 pairs of cranial nerve and 31 pairs of peripheral spinal nerves

nerve

one or more bundles of neurons that connect the brain and spinal cord with other parts of the body

tracts

a bundle or group of nerve fibers located within the brain or spinal cord

ganglion

nerve center made up of clusters of nerve cell bodies outside the central nervous system

plexus

network of intersecting spinal nerves

receptors

sites in the sensory organs that receive external stimulation

stimulus

anything that excites a nerve and causes an impulse

relfex

automatic, involuntary response to change either inside or outside the body

neurons

basic cells of the nervous system that allow different parts of the body to communicate with each other

dendrites

root like processes that receive impulses and conduct them to the cell body

axon

process that conducts impulses away from the nerve cell

terminal end fibers

branching fibers at the end of the axon that lead the impulse form the axon to the synapse

glial cells

provides support and protection for neurons

• surrounds neurons to hold in pace

• supply nutrients and oxygen to neurons

• insulate one neuron form another

• destroy and remove dead neurons

myelin sheaths

protective covering made up of glial cells

the myelinated nerve fibers are known as

white matter

the un-myelinated nerve fibers are known as

grey matter

meninges

system of membrane that enclose the brain and spinal cord

dura matter

thick tough outermost membrane of the meninges

arachnoid membrane

resembles a spiderweb, second layer of the meninges

pia matter

third layer of the meninges, nearest to the brain, has delicate connective tissues with rich supply of blood vessels

cerebrospinal fluid

clear colorless watery fluid that flows throughout the brain and around the spinal cord

• cools and cushions brain and spinal cord from shock or injury

• nourish the brain and spinal cord by transporting nutrients

cerebrum

largest and uppermost portion of the brain

• thought, judgement, memory and emotion

• controlling motor and sensory function

cerebral cortex

made of gray matter, is the outer layer of the cerebrum

gyri

elevated fold of gray matter

sulci

fissures of the cerebral cortex

the two cerebral hemispheres are connected at the

corpus callosum

left cerebral hemispheres

controls functions of the right side of the body

right cerebral hemisphere

controls functions of the left side of the body

cerebral lobes

• frontal lobe

• parietal lobe

• occipital lobe

• temporal lobe

front lobe

controls skilled motor functions memory and behavior

parietal lobe

recieves and interprets nerve impulses from sensory receptors in tongue, skin and muscles

occipital lobe

controls eyesight

temporal lobe

controls hearing smell and ability to create store and access new information

thalamus

located below the cerebrum, produces sensation by relaying impulses to and from the cerebrum and the sense organ

hypothalmus

located below the thalamus

regulates: heart rate, blood pressure, respiratory, emotional responses, body temperature, hunger, thirst, sleep cycle and endocrine system activity

midbrain and pons

provides conduction pathways to and from the higher and lower centers in the brain

medulla oblongata

located at the lowest part of the brain stem and is connect to the spinal cord

spinal cord

long fragile tube like structure that begins at the end of the brain stem and continues down

three types of specialized peripheral nerves

• autonomic

• sensory

• somatic / motor nerves

autonomic nerve fibers

carries instructions to the organs and glands from autonomic nervous system

sensory nerve fibers

receive external stimuli

somati nerve fibers

convey information that control the body’s voluntary muscular movements

31 pairs of peripheral spinal nerves

• C1 - C8

• T1 - T12

• L1 - L5

• S1 - S5

divisions of the autonomic nervous system

sympatic nerves and parasympathetic nerves

autonomic nervous system

controls the involuntary actions of the body

sympatheic nerves

starts the fight or flight response and preps the body for emergency response

parasympathetic nerves

calms the body after the flight or fight

caus/o

burning or burn

cerebr/o

cerebrum, brain

concuss/o

shaken together, violently agitated

contus/o

bruise

encephal/o

brain

-esthet/o

feeling, nervous sensation, sense of perception

-graphy

process of producing a picture or record

mening/o

membrane, meninges

myel/o

spinal cord, bone marrow

neur/i, neur/o

nerve, nerve tissue

phobia

abnormal fear

psych/o

mind

radicul/o

root or nerve root

tropic

having an affinity for