Medical Terminology - Unit 10

Nervous System

central nervous system

brain and spinal cord

peripheral nervous system

cranial/spinal nerves, conscious/automatic functions

nerve

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

ascending nerve tracts

carry nerve impulses toward the brain

descending nerve tracts

carry nerve impulses away from the brain

ganglion

a nerve center made up of a cluster of nerve cell bodies outside of the CNS

innervation

supply of nerves to a specific body part

plexus

a network of intersecting spinal nerves

receptors

sites in sensory organs that receive external stimulation

stimulus

anything that excites a nerve and causes an impulse

reflex

an automatic response to some change either inside or outside of the body

neurons

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

dendrites

root-like parts that receive impulses and conduct them to the body

axon

part that conducts impulses away from the nerve cell

terminal end fibers

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

synapse

space between two neurons

neurotransmitters

chemical substances that make messages cross from synapse to target receptor

acetylcholine

releases in spine and neuromuscular junctions, plays a role in muscle action

dopamine

released in the brain and plays a role in motivation, pleasure, and muscle movement

endorphins

produced by the brain to relieve pain

norepinephrine

alertness and arousal, increases blood pressure and heart rate by releasing stored glucose in response to stress

serotonin

released in the brain and has roles in hunger, sleep, and pleasure recognition

glial cells

hold in place, supply oxygen, insulate, and destroy neurons

myelin sheath

protective covering made up of glial cells

white matter

myelinated

gray matter

unmyelinated

meninges

system of membranes that enclose the brain and spine

dura mater

thick, tough, outermost membrane of the meninges

arachnoid membrane

resembles a web, second layer of the meninges

pia mater

third layer of the meninges, located nearest to the brain and spinal cord

cerebrospinal fluid

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

cerebrum

largest and uppermost portion of the brain, responsible for judgement, memory, thought, emotion

cerebral cortex

made up of grey matter, outer layer of cerebrum

gyri

gray mater folds

sulci

fissures of the cerebral cortex

cerebral hemispheres

connected at lower midpoint by corpus callosum

left hemisphere

controls functions on right side

right hemisphere

controls functions on left side

cerebral lobes

each lobe is named for the bone of cranium that covers it

frontal lobe

controls skilled motor functions, memory, and behavior

parietal lobe

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

temporal lobe

controls hearing, smell, and the ability to store and access new information

thalamus

located below the cerebrum

hypothalamus

located below the thalamus (regulates autonomic nervous system, emotional responses, body temperature, food intake, water balance, sleep cycle, pituitary and endocrine activity)

cerebellum

second largest part of the brain, located at the back of the head

brainstem

stalk-like portion of the brain that connects hemispheres with spinal cord

midbrain and pons

provide conduction pathways to and from higher and lower centers in brain

medulla oblongata

located at the lowest part of the brainstem, controls survival function

spinal cord

long, fragile, tube-like structure that begins at the end of the brainstem and continues down almost to the bottom of the spinal column

autonomic nerve fibers

carry instructions to the organs and glands from ans

sensory nerve fibers

receive external stimuli, such as how something feels, and transmit this information to the brain where it is interpreted

somatic nerve fibers

convey information that controls the body’s voluntary muscular movements

cranial nerves

originate from the under-surface of the brain

peripheral spinal nerves

grouped together and named based on the region of the body they innervate

anesthesiologist

a physician who specializes in administering anesthetic agents before and during surgery

anesthetist

a medical professional who specializes in administering anesthesia but is not a physician

neurologist

a physician who specializes in diagnosing and treating diseases and disorders of the nervous system

psychiatrist

physician who specializes in diagnosing and treating chemical dependencies, emotional problems, and mental illness

psychologist

has a doctoral degree (PhD or PsyD) but is not a medical doctor (evaluates mental problems/illnesses)

social worker

a trained therapist with a masters degree

cephalalgia

headache

migraine

characterized by throbbing pain on one side of the head

cluster headache

intensely painful headaches that affect one side of the head and may be associated with tearing of the eyes and nasal congestion

encephalocele

a congenital herniation of brain tissue through a gap in the skull

meningocele

the congenital herniation of the meninges through a defect in the skull or spinal column

hydrocephalus

a condition in which excess cerebrospinal fluid accumulates in the ventricles of the brain

Chiari malformation

a congenital condition in which part of the cerebellum extends down into the spinal canal

encephalitis

an inflammation of the brain, can be caused by a viral infection such as rabies

Reye’s syndrome

(RS) a serious and potentially deadly disorder in children that is characterized by vomiting and confusion, can follow a viral illness

tetnanus

lockjaw, acute and potentially fatal infection of the central nervous system caused by a toxin produced by the tetanus bacteria

cognition

describes the mental activities associated with thinking, learning, and memory

vascular dementia

dementia caused by stroke or blood flow restriction to the brain

Alzheimer’s

(AD) a group of disorders involving parts of the brain that control thoughts, memory, and language

Parkinson’s

(PD) chronic, degenerative central nervous disorder characterized by fine muscle tremors, rigidity, and a slow or shuffling gait

tremor

a repetitive, involuntary muscle movement usually involving the hands, arms, head, or face

lewy body dementia

second most common type of dementia, occurs when abnormal proteins interfere with cell function in the brain

amyotrophic lateral sclerosis

rapidly progressive neurological disease that attacks the nerve cells responsible for controlling voluntary muscles

cerebral contusion

bruising of the brain tissue from a head injury that causes the brain to bounce against the skull

cranial hematoma

a collection of blood trapped in the tissues of the brain

traumatic brain injury

(TBI) a blow to the head or penetrating head injury that damages the brain

levels of consciousness

(LOC) describe the measurement of response to arousal and stimulus

lethargy

a lowered level of consciousness marked by listlessness, drowsiness, and apathy

stupor

an unresponsive state from which a person can be aroused only briefly despite vigorous, repeated attempts.

syncope

fainting, brief loss of consciousness caused by lack of blood to the brain

coma

a profound (deep) state of unconsciousness marked by the absence of spontaneous eye movements, no response to painful stimuli, and the lack of speech

glioblastoma

a type of fast-growing, malignant brain tumor that forms from glial cells

delirium

an acute condition of confusion, disorientation, disordered thinking and memory, agitation, and hallucination

malignant brain tumor

destroys brain tissue

intracranial pressure

the amount of pressure inside the skull

cerebrovascular accident

(CVA) stroke, brain damage that occurs when blood flow to the brain is disrupted

ischemic stroke

the most common type of stroke in older people, occurs when the flow of blood to the brain is blocked by the narrowing or blockage of an artery

transient ischemic attack

(TIA) mini-stroke, temporary interruption of blood supply to the brain

aphasia

often caused by brain damage associated with a stroke, is the loss of the ability to speak, write, and/or comprehend the written or spoken word

insomnia

prolonged or abnormal inability to sleep

parasomnia

sleep disorders that occur while falling asleep, during sleep, or while waking from sleep

somnambulism

sleepwalking

myelitis

inflammation of the spinal cord

poliomyelitis

a highly contagious viral infection of the brainstem and spinal cord that sometimes leads to paralysis

myelosis

tumor of the spinal cord

radiculitis

punched nerve