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.