SECTION 6 NERVOUS SYSTEM

The center of the nervous system is the brain which coordinates and controls all activities

of the body. Should the brain stop functioning, death would occur. The structures of this

system include the brain, spinal cord, nerves, and sensory organs. Three parts make up

this system: the central nervous system (CNS), the peripheral nervous system (PNS), and

the autonomic nervous system (ANS).

Word Elements We will first look at some of the word elements that might be used in this

system. Listen as each word element is being pronounced.

arachn/o (a rak no) means spider or spider web

arachno

athet/o (ath’ e to) means uncontrolled

atheto

ax/o (ak so) means axis or main stem

axo

caus/o, caust/o (kaw so, kaw sto) means burning

causo, causto

-cele means hernia, swelling, tumor, cyst

cele

cephal/o (sef a lo) means head

cephalo

cerebell/o (ser e bel o) means cerebellum (ser e bel um)

cerebello

cerebr/o (ser e bro) means brain or cerebrum (ser e brum, ser e brum)

cerebro

concuss/o (kon kush o) means violently shaken

concusso

contus/o (kon too’ so) means bruise

contuso

convolut/o (kon vo loo’ to) means coiled or twisted

convoluto

cortic/o (kor ti ko) means cortex or outer region

cortico

dendr/o (den dro) means branching or resembling a tree

dendro

dur/o (du ro) means dura mater

duro

encephal/o (en sef a lo) means brain

encephalo

epi- (ep i) means over or upon

epi

-esthesia (es the ze a) means sensation or feeling

esthesia

gangli/o, ganglion/o (gang le o, gang le on o) means swelling or ganglion

ganglio, gangliono

gli/o (gli o) means glue

glio

gyr/o (ji ro) means turning or folding

gyro

hemat/o (he ma to) means blood

hemato

hydro- (hi dro) means pertaining to water or hydrogen

hydro

-lepsy (lep se) means seizure

lepsy

medull/o (med u lo, me dul o) means inner section, soft, marrow

medullo

mening/o, meningi/o (men in go, men in je o) means meninges (membranes that enclose the

brain and spinal cord

meningo, meningio

myel/o (mi e lo) means spinal cord or bone marrow

myelo

narc/o (nar ko) means numbness or stupor

narco

neur/o (nu ro) or neur/i (nu ri) means nerve or nervous system

neuro, neuri

noct/i (nok ti) means night

nocti

-oid (oyd) means like or resembling

oid

-phasia (fa ze a) means speak or speech

phasia

plex/o (pleks o) means plexus or network

plexo

poli/o (pol e o) means gray matter of brain and spinal cord

polio

radicul/o (ra dik u lo) means root as in nerve root

radiculo

somn/i, somn/o (som ni, som no) means sleep

somni, somno

sub- (sub) means below, beneath, under

sub

sulc/o (sul ko) means groove or furrow

sulco

synaps/o, synapt/o (sin ap so, sin ap to) means point of contact

synapso, synapto

thalam/o (thal a mo) means thalamus or inner room

thalamo

Nervous System Words

agnosia (ag no’ ze a) is the loss of comprehension of auditory, visual, or other sensations

although the sensory sphere is intact

a- means without

gnosia means knowledge

agnosia

Alzheimer’s disease (alts’ hi merz) is a chronic, organic mental disorder that includes

progressive memory loss, impaired thinking, and personality changes

Alzheimer’s disease

amnesia (am ne’ ze a) is a loss of memory

amnesia

amyotrophic (a mi” o tro’ fik) lateral sclerosis (also known as Lou Gehrig’s disease)

abbreviated ALS—is a degenerative disease of the motor neurons in which the patient

becomes progressively weaker until completely paralyzed

amyotrophic means pertaining to muscular atrophy

lateral means pertaining to the side

scler/o means hard

-osis means condition

amyotrophic lateral sclerosis

apathy (ap’ a the) means indifference or lack of emotion

a- means without

-pathy means feeling

apathy

aphasia (a fa’ ze a) is the absence or impairment of the ability to communicate through

speech

a- means without

phasia means to speak or speech

aphasia

apraxia (a prak’ se a) is the inability to perform purposive movements although there is no

sensory or motor impairment

a- means without

praxia refers to action

apraxia

arachnoid membrane (a rak’ noyd) is the second layer of the meninges and it resembles a

spider web

arachn/o means spider web

oid means resembling or like

arachnoid membrane

athetosis (ath e to’ sis) is a condition in which irregular, slow, twisting, snakelike

movements occur in the upper extremities (usually)

athet/o means uncontrolled

-osis means condition

athetosis

autonomic nervous system (aw to nom’ ik)--abbreviated ANS--consists of ganglia (gang’ gle

a) on either side of the spinal cord

autonomic nervous system

axon (ak’ son) is the neuron process that conducts impulses away from the cell body

axon

Bell’s palsy is a paralysis of the seventh cranial or facial nerve, causing a unilateral

drooping of the side of the face affected by the paralysis

Bell’s palsy

brainstem is the stalklike portion of the brain that connects cerebral hemispheres with the

spinal cord

brainstem

central nervous system—abbreviated CNS—consists of the spinal cord and brain

central nervous system

cephalalgia (sef a lal’ je a) is pain in the head or a headache; may also be called

cephalodynia (sef” a lo din’ e a)

cephal/o means head

-algia means pain

cephalalgia

cerebellum (ser e bel’ um) is located in the lower back of the cranium below the cerebrum

(ser’ e brum, ser e’ brum). It coordinates muscle activity for smooth and steady

movements.

cerebellum

cerebral palsy (ser e’ bral pawl’ ze) is a nonprogressive paralysis that has resulted from

brain defect or lesion present at birth or shortly after birth

cerebral means pertaining to the brain

palsy means paralysis

cerebral palsy

cerebral contusion (ser e’ bral kon too’ shun) is bruising of the brain tissue due to a head

injury

cerebral means pertaining to the brain

contus/o means bruise

cerebral contusion

cerebrospinal fluid (ser” e bro spi’ nal) —abbreviated CSF—is a colorless, clear, watery

fluid produced by special capillaries within the brain ventricles

cerebr/o means brain

spinal means pertaining to the spine

cerebrospinal fluid

cerebrum (ser’ e brum, ser e’ brum) is the largest part of the brain and is responsible for

the highest level of thought

cerebr/o means brain

cerebrum

coma (ko’ ma) is a deep state of unconsciousness marked by the absence of spontaneous eye

movements, response to stimuli, and/or vocalization

coma

concussion (kon kush’ un) is a head injury resulting from impact with an object

concuss/o means violently shaken

concussion

conscious (kon’ shus) means being awake and aware of surroundings

conscious

convolution (kon” vo loo’ shun)--also known as gyrus--means a turn, fold, or coil of

anything that is rolled, as a scroll

convolution

demyelination (de mi’ e lin a’ shun) is the destruction or loss of the myelin (mi’ e lin) sheath

from the myelinated (mi’ e li nat’ ed) fibers due to disease

demyelination

dendrite (den’ drit) is the part of the neuron that conducts impulses to the cell body

dendr/o means branching

dendrite

dura mater (du’ ra ma’ tur) is the outermost membrane of the meninges

dur/o means pertaining to the dura mater

dura mater

dysphasia (dis fa’ ze a) is the impairment of speech resulting from a brain lesion

dys- means bad, labored, painful, difficult

-phasia means to speak or speech

dysphasia

electroencephalography (e lek tro en sef a lo gra fe) —also known as EEG—is the process of

recording brain-wave activity

electr/o means electric

encephal/o means brain

-graphy means the procedure of recording or writing

electroencephalography

electroshock therapy—also known as electroconvulsive therapy (abbreviated ECT)

produces a controlled convulsion as an electric current passes through the brain

electroshock therapy

encephalogram (en sef’ a lo gram) is the record made from an EEG

encephal/o means brain

gram means record or image

encephalogram

encephalopathy (en sef” a lop’ a the) is any degenerative disease of the brain

encephal/o means brain

-pathy means disease or feeling

encephalopathy

epidural (ep i doo ral) means outside the dura mater

epi- means upon, over

dural means pertaining to the dura mater

epidural

epilepsy (ep’ i lep” se) is a group of disorders that are characterized by recurrent episodes

of seizures

epilepsy

fissure (fish’ ur)—also known as sulcus—is a groove or natural division, cleft, or slit

fissure

frontal lobe consists of the four main convolutions in front of the cerebrum that control

motor functions

frontal lobe

ganglion (gang’ le on) is a mass of nervous tissue mainly composed of nerve-cell bodies and

lying outside the brain or spinal cord

ganglion

grand mal epilepsy is one of two types of epilepsy that is characterized by tonic-clonic

(klon’ ik) seizures

grand mal epilepsy

gray matter is what nerves are called that do not have myelin sheath protective coverings

on them

gray matter

homeostasis (ho” me o sta’ sis) refers to the state of equilibrium or the process of

maintaining a constant internal environment in the body

home/o means likeness

-stasis means standing

homeostasis

hydrocephalus (hi dro sef’ a lus) is an abnormally increased amount of fluid within the

brain

hydr/o means fluid

cephalus means referring to the brain

hydrocephalus

hypothalamus (hi” po thal’ a mus) is the portion of the diencephalon comprising the

ventral wall of the third ventricle. It is located below the thalamus and controls vital body

functions.

hyp/o means under, below

hypothalamus

innervation (in” er va’ shun) is the nerve supply to a body part and also the stimulation of

a body part

innervation

lethargy (leth’ ar je) is a lowered level of consciousness where the patient is listless, drowsy,

and apathic

lethargy

lobectomy (lo bek’ to me) means surgical removal of a lobe of the brain

lob/o means lobe

-ectomy means to surgically remove

lobectomy

lobotomy (lo bot’ o me) means to surgically cut into a lobe

lob/o means lobe

o/tomy means to cut into; incision

lobotomy

medulla oblongata (me dul’ la ob” long ga’ ta) is the lower portion of the brainstem that

controls the basic vital functions

medull/o means inner portion

oblongata means oblong

medulla oblongata

meninges (men in’ jez) are the three layers of membrane that enclose the brain and spinal

cord; the three layers are: dura mater—the external layer, arachnoid membrane—the

middle layer, and pia (pe’ a) mater (ma’ tur) —the internal layer

mening/o means meninges or the covering of the brain and spinal cord

meninges

meningitis (men in ji’ tis) inflammation of the membranes of the spinal cord or brain

mening/o means meninges (membranes around the spinal cord or brain)

-itis means inflammation

meningitis

migraine headache (mi’ gran) is a sudden, severe, sharp headache usually only on one side

migraine headache

mnemonic (ne mon’ ik) is a device to help recall or aid memory

mnemonic

multiple sclerosis (skle ro’ sis) —abbreviated MS—is an inflammatory disease of the central

nervous system in which infiltrating lymphocytes, mainly T cells and macrophages, degrade

the myelin (mi’ e lin) sheath of nerves

scler/o means hard

-osis means condition

multiple sclerosis

myelin sheath (mi’ e lin) is a fatlike substance forming a sheath around the axons of certain

nerves

myelin sheath

myelitis (mi” e li’ tis) is the inflammation of the spinal cord or bone marrow

myel/o means spinal cord or bone marrow

-itis means inflammation

myelitis

myelography (mi’ e log’ ra fe) is the diagnostic study of the spinal cord after injecting a

contrast medium into the body

myel/o means spinal cord or brain

-graphy means the procedure of recording or writing

myelography

narcolepsy (nar’ ko lep” se) is recurrent uncontrollable seizures of drowsiness and sleep

narc/o means numbness or stupor

-lepsy means seizure

narcolepsy

neuralgia (nu ral’ je a) means pain in a nerve

neur/o means nerve

-algia means pain

neuralgia

neuritis (nu ri’ tis) is an inflammation of a nerve

neur/o means nerve

-itis means inflammation

neuritis

neuroglia (nu rog’ le a) (also known as glial cell) is the tissue that forms the interstitial

supporting elements—cells and fibers—of the nervous system

neur/o means nerve

gli/o means glue

neuroglia

neuroplasty (nu’ ro plas” te) is the surgical repair of a nerve

neur/o means nerve

-plasty means surgical repair or correction

neuroplasty

neurorrhaphy (nu ror’ a fe) is the suturing of a nerve

neur/o means nerve

-rrhaphy means to sew or suture

neurorrhaphy

neurotransmitter (nu” ro trans’ mit er) is a chemical substance that makes it possible for

an impulse to jump across the synapse from one neuron to another

neur/o means neuron or nerve

neurotransmitter

occipital lobe (ok sip’ i tal) is the posterior lobe of the brain that is shaped like a three-sided

pyramid. It controls eyesight.

occipital lobe

paralysis (pa ral’ i sis) is the loss of the ability to use voluntary movement in a muscle

because of injury or disease; it may be temporary or permanent.

paralysis

paresthesia (par” es the’ ze a) is the sensation of burning, numbness, and tingling usually

with no apparent physical cause

par means beside

esthesia means sensation or feeling

paresthesia

parietal lobe (pa ri’ e tal) is the division of each side of the brain lying beneath each

parietal bone. It receives and interprets nerve impulses from sensory receptors.

parietal lobe

Parkinson’s disease is a slowly progressive and degenerative central nervous system

disorder

Parkinson’s disease

peripheral nervous system (per if’ er al) —abbreviated PNS—consists of the spinal nerves

and cranial nerves

peri- means around or about

peripheral nervous system

petit mal epilepsy (pet e’ mal) —also known as absence epilepsy—is characterized by a

brief altered state of consciousness with eye or muscle fluttering but without convulsive

movements of generalized seizure

petit mal epilepsy

pia mater (pe’ a ma’ tur) is the innermost membrane of the three meninges and is located

closest to the brain and spinal cord. It has a rich supply of blood vessels.

pia means tender, soft

pia mater

plexus (pleks’ us) is the singular form (the plural form is plexi). It is a network of nerves,

blood, or lymphatic vessels.

plexus

poliomyelitis (pol” e o mi el i’ tis) is the inflammation of the gray matter of the spinal cord

poli/o means gray matter of brain and spinal cord

myel/o means spinal cord or bone marrow

-itis means inflammation

poliomyelitis

pons (ponz) is located in the brainstem at the base of the brain and acts as a bridge

allowing nerves to cross over so that one side of the brain can control the opposite side of

the body

pons

radiculitis (ra dik” u li’ tis) is an inflammation of the root of a spinal nerve

radicul/o means root, nerve root

-itis means inflammation

radiculitis

receptor (re sep’ tor) is a sensory organ—such as eye, ear, skin, or taste bud—that receives

external stimulation and then transmits it to a sensory neuron

receptor

SAM stands for the neurons responsible for Sending (sensory), Accessing (connecting), and

Moving (motor)

SAM

sciatica (si at’ i ka) is an inflammation of the sciatic nerve, usually associated with pain,

running along the thigh and leg

sciatica

seizure (se’ zhur)--also known as a convulsion--is an involuntary contraction of a muscle or

groups of muscles that is sudden and violent in nature

seizure

somnolence (som’ no lens) is prolonged drowsiness or sleepiness

somnolence

stimulus (stim’ u lus) is the singular form. The plural form is stimuli. It means something

that activates or excites a nerve that in turn causes an impulse.

stimulus

stroke—also known as cerebrovascular accident (ser” e bro vas’ cu lar) or CVA—happens

when the flow of blood to the brain is disrupted because of a ruptured or blocked blood

vessel

stroke, cerebrovascular accident, CVA

stupor (stu’ por) is a state of impaired consciousness with a lack of unresponsiveness to

environmental stimuli

stupor

subarachnoid space (sub” a rak’ noyd) is located below the arachnoid membrane and

above the pia mater. It contains the cerebrospinal fluid.

sub- means under, below

arachn/o means spider, spider web

-oid means resembling

subarachnoid space

subdural space (sub du’ ral) is located below the dura membrane and above the arachnoid

membrane

sub- means below, beneath

dural means pertaining to the dura mater

subdural space

synapse (sin’ aps) is the point of juncture between two neurons in the neural pathway

synaps/o means point of contact

synapse

syncope (sin’ ko pe)--also known as fainting--is a brief loss of consciousness caused by a

lack of oxygen in the brain

syncope

temporal lobe (tem’ por al) is a lobe of the brain that is located laterally and below the

frontal and occipital lobes. It controls the senses of hearing and smell.

temporal lobe

tetanus (tet’ a nus)--also known as lockjaw--is an acute infectious disease due to the toxin

of tetanus bacillus. It can be prevented through immunization.

tetanus

thalamus (thal’ a mus) is the largest subdivision of the diencephalon (di” en sef’ a lon) on

either side. It monitors sensory stimuli by suppressing some and magnifying others.

thalamus

tic douloureux (tik doo loo roo) is the inflammation of the fifth cranial (trigeminal) nerve

usually resulting in neuralgia of the nerve

tic douloureux

transient ischemic (is ke’ mik) attack—also known as TIA—is the temporary interference

with blood supply to the brain

isch means to hold

emic means pertaining to blood

transient ischemic attack

tremor (trem’ or, tre’ mor) is an involuntary movement of a part or parts of the body

tremor

ventricle (ven’ trik l) means a small cavity. In the nervous system it refers to the four small

cavities located within the middle region of the brain that contain cerebrospinal fluid.

ventricle

white matter--also called myelin sheath--is a protective covering over some nerve cells (if

nerves do not have myelin sheath they are called gray matter)

white matter

This ends the section on the Nervous System. If you have any questions, please ask your

instructor for further clarification or refer to your textbook. You should repeat this section

as many times as you feel is necessary to feel comfortable with the meaning and

pronunciation of the words presented.