Body Parts

Organs of the Central Nervous System

brain

major portion of the central nervous system.

cerebrum

largest portion of the brain, divided into left and right hemispheres.  The cerebrum controls the skeletal muscles, interprets general senses (such as temperature, pain, and touch), and contains centers for sight and hearing.  Intellect, memory, and emotional reactions also take place in the cerebrum.

ventricles

spaces within the brain that contain a fluid called cerebrospinal fluid.  The cerebrospinal fluid flows through the subarachnoid space around the brain and spinal cord.

cerebellum

located under the posterior portion of the cerebrum.  Its function is to assist in the co-ordination of skeletal muscles and to maintain balance (also called hindbrain).

brainstem

stem-like portion of the brain that connects with the spinal cord.  Then of the 12 cranial nerves originate in the brainstem.

pons

literally means bridge.  It connects the cerebrum with the cerebellum and brainstem.

medulla oblongata

located between the pons and the spinal cord.  It contains centers that control respiration, heart rate, and the muscles in the blood vessel walls, which assist in determining blood pressure.

midbrain

most superior portion of the brainstem.

cerebrospinal fluid

clear, colorless fluid contained in the ventricles that flow through the subarachnoid space around the brain and spinal cord.  It cushions the brain and spinal cord from shock, transports nutrients, and clears metabolic waste.

spinal cord

passes through the vertebral canal extending from the medulla oblongata to the level of the second lumbar vertebra.  The spinal cord conducts nerve impulses to and from the brain and initiates reflex action to sensory information without input from the brain.

meninges

three layers of membrane that cover the brain and spinal cord.

dura mater

tough outer layer of the meninges.

arachnoid

delicate middle layer of the meninges.  The arachnoid membrane is loosely attached to the pia mater by web-like fibers, which allow for the subarachnoid space.

pia mater

thin inner layer of the meninges.

organs of the peripheral nervous system

nerve

cord-like structure that carries impulses from one part of the body to another.  There are 12 pairs of cranial nerves and 31 pairs of spinal nerves.

ganglion (pl. ganglia)

group of nerve cell bodies located outside the central nervous system.

Prefixes

tetra-

four

Combining Forms

cerebell/o

cerebellum

cerebr/o

cerebrum, brain

dur/o

hard, dura mater

encephal/o

brain

gangli/o, ganglion/o

ganglion

mening/i, mening/o

meninges

myel/o

spinal cord

neur/o

nerve

radic/o, radicul/o, rhiz/o

nerve root (proximal end of a peripheral nerve, closest to the spinal cord)

esthesi/o

sensation, sensitivity, feeling

ment/o, phren/o, psych/o

mind

mon/o

one

phas/o

speech

poli/o

gray matter

quadr/i

four

Suffixes

-iatrist

specialist, physician

-iatry

treatment, specialty

-ictal

seizure, attack

-paresis

slight paralysis

Medical Terms – not built from word parts

Alzheimer disease (AD)

disease characterized by early senility, confusion, loss of recognition of persons or familiar surroundings, restlessness, and impaired memory.

amyotrophic lateral sclerosis (ALS)

progressive muscular atrophy caused by hardening of nerve tissue on the lateral columns of the spinal cord.  Also called Lou Gehrig disease.

Bell palsy

paralysis of muscles on one side of the face, usually a temporary condition.  Symptoms include a sagging mouth on the affected side and non-closure of the eyelid.

cerebral aneurysm

aneurysm in the cerebrum.

cerebral palsy (CP)

condition characterized by lack of muscle control and partial paralysis, caused by a brain defect or lesion present at birth or shortly after.

cereberovascular accident (CVA)

interruption of blood supply to the brain caused by a cerebral thrombosis, cerebral embolus, or cerebral hemorrhage.  The patient may experience mild to severe paralysis.  Also called stroke, or brain attack.

epilepsy

disorder in which the main symptom is recurring seizures.

hydrocephalus

increased amount of cerebrospinal fluid in the ventricles of the brain, which can cause enlargement of the cranium.

multiple sclerosis (MS)

degenerative disease characterized by sclerotic patches along the brain and spinal cord.

neurosis (pl. neuroses)

emotional disorder that involves an ineffective way of coping with anxiety or inner conflict.

Parkinson disease (PD)

chronic degenerative disease of the central nervous system.  Symptoms include resting tremors of the hands and feet, rigidity, expressionless face, and shuffling gait.  It usually occurs after the age of 50 years.

psychosis (pl. psychoses)

major mental disorder characterized by extreme derangement, often with delusions and hallucinations.

Reye syndrome

disease of the brain and other organs such as the liver.  Affects children and adolescents.  The cause is unknown, but it typically follows a viral infection.

sciatica

inflammation of the sciatic nerve, causing pain that travels from the thigh through the leg to the foot and toes.  Can be caused by injury, infection, arthritis, herniated disk, or from prolonged pressure on the nerve from sitting for long periods.

shingles

viral disease that affects the peripheral nerves and causes blisters on the skin that follow the course of the affected nerves.  Also called herpes zoster.

transient ischemic attach (TIA)

sudden deficient supply of blood to the brain lasting a short time.  The symptoms may be similar to those of CVA, but with TIA the symptoms are temporary and the usual outcome is complete recovery.

computed tomography of the brain (CT scan)

process that includes the use of a computer to produce a series of images of the tissues of the brain at any desired depth.  The procedure is non-invasive, painless, and particularly useful in diagnosing brain tumors.

magnetic resonance imaging of the brain (MRI scan)

a non-invasive technique that produces cross-sectional and sagittal images of soft tissues of the brain by magnetic waves.  Unlike CT scan, MRI produces images without use of radiation.  It is used to visualize tumors, edema, multiple sclerosis, and herniated disks.

positron emission tomography of the brain (PET scan)

an imaging technique with a radioactive substance that permits viewing a slice of the brain to examine blood flow and metabolic activity.  Images are projected on a viewing screen.

evoked potential studies (EP studies)

a group of diagnostic tests that measure changes and responses in brain waves elicited by visual, auditory, or somatosensory stimuli.  Visual evoked response (VER) is a response to visual stimuli.  Auditory evoked response (AER) is a response to auditory stimuli.

lumbar puncture (LP)

insertion of a needle into the subarachnoid space usually between the third and fourth lumbar vertebrae.  It is performed for many reasons, including the removal of cerebrospinal fluid for diagnostic purposes.

afferent

conveying toward a center (for example, afferent nerves carry impulses to the central nervous system).

ataxia

lack of muscle coordination.

cognitive

pertaining to the mental processes of comprehension, judgment, memory, and reason.

coma

state of profound unconsciousness.

concussion

jarring or shaking that results in an injury.  Brain concussions are caused by slight or severe head injury; symptoms include vertigo and loss of consciousness.

conscious

awake, alert, aware of one’s surroundings.

convulsion

sudden, involuntary contraction of a group of muscles (synonymous with seizure).

dementia

loss of cognitive abilities.

disorientation

a state of mental confusion as to time, place, or identity.

efferent

conveying away from the center (for example, efferent nerves carry information away from the central nervous system).

gait

a manner or style of walking.

incoherent

unable to express one’s thoughts or ideas in an orderly, intelligible manner.

paraplegia

paralysis from the waist down caused by damage to the lower level of the spinal cord.

seizure

sudden attack with an involuntary series of contractions (synonymous with convulsion).

shunt

tube implanted in the body to redirect the flow of a fluid.

syncope

fainting or sudden loss of consciousness caused by lack of blood supply to the cerebrum.

unconsciousness

state of being unaware of surroundings and incapable of responding to stimuli as a result of injury, shock, or illness.

Common Behavioral Health Disorders

anorexia nervosa

an eating disorder characterized by failure to maintain body weight, intensive fear of gaining weight, pronounced desire for thinness, and, in females, amenorrhea.

anxiety disorder

an emotional disorder characterized by feelings of apprehension, tension, or uneasiness arising typically from the anticipation of unreal or imagined danger.

attention deficit-hyperactivity disorder (ADHD)

a disorder of learning and behavioural problems characterized by marked inattention, impulsiveness, and hyperactivity.

bipolar disorder

a major psychological disorder typified by a disturbance in mood.  The disorder is manifested by manic and depressive episodes that may alternate or may occur simultaneously.

bulimia nervosa

an eating disorder characterized by uncontrolled binge eating followed by purging (induced vomiting).

major depression

a mood disturbance characterized by feelings of sadness, despair, and discouragement.  Depression ranges from normal feelings of sadness (resulting from and proportional to personal loss or tragedy), through dysthymia (depressive neurosis), to major depression.

obsessive-compulsive disorder (OCD)

a disorder characterized by intrusive, unwanted thoughts that result in the tendency to perform repetitive acts or rituals (compulsions), usually as a means of releasing tension or relieving anxiety.

panic attack

an episode of acute anxiety, occurring unpredictably, with feelings of acute apprehension, dyspnea, dizziness, sweating, and/or chest pain.

phobia

a marked and persistent fear that is excessive or unreasonable cued by the presence or anticipation of a specific situation or object.

pica

compulsive eating of non-nutritive substances such as clay or ice.  This condition is often a result of an iron deficiency.  When iron deficiency is the cause of pica, the condition will disappear in 1 or 2 weeks when treated with iron therapy.

posttraumatic stress disorder (PTSD)

a disorder characterized by an acute emotional response to a traumatic event or severe emotional stress such as an airplane crash, repeated physical or emotional trauma, or military combat.  Symptoms include anxiety, sleep disturbance, difficulty concentrating, and depression.

schizophrenia

any one of a large group of psychotic disorders characterized by gross distortions of reality, disturbance of language ande communication, withdrawal from social interaction, and the disorganization and fragmentation of thought, perception, and emotional reaction.

somatoform disorders

physical symptoms for which no known physical cause exists.

Abbreviations

AD

Alzheimer disease

ADHD

attention deficit-hyperactivity disorder

ALS

amyotrophic lateral sclerosis

CNS

central nervous system

CP

cerebral palsy

CSF

cerebrospinal fluid

CVA

cereberovascular accident

EchoEG

echoencephalography

EEG

electroencephalogram

EP studies

evoked potential studies

LP

lumbar puncture

MRI scan

magnetic resonance imaging scan

MS

multiple sclerosis

OCD

obsessive-compulsive disorder

PD

Parkinson disease

PET scan

positron emission tomography scan

PNS

peripheral nervous system

PTSD

posttraumatic stress disorder

TIA

transient ischemic attack