Medical Terminology, Chapter 10, The Nervous System

ACE
types of neurons: Afferent, Connecting, Efferent

acrophobia
an excessive fear of being in high places

afferent neurons (afferent means toward)
sensory neurons; emerge from sensory organs and the skin to carry the impulses from the sensory organs toward the brain and spinal cord

agoraphobia
an excessive fear of situations in which having a panic attack seems likely and/or dangerous or embarrassing

alcoholism
chronic alcohol dependence with specific signs and symptoms upon withdrawal

Alzheimer’s disease
disorder associated with degenerative changes in the brain structure that lead to progressive memory loss, impaired cognition, and personality changes

amnesia
a memory disturbance characterized by a total or partial inability to recall past experiences

amobarbital
a barbiturate used as a sedative and hypnotic

amyotrophic lateral sclerosis (ALS)
a degenerative disease in which patients become progressively weaker until they are completely paralyzed; also known as Lou Gehrig’s disease

anesthesia
the absence of normal sensation, especially sensitivity to pain, that is induced by the administration of an anesthetic

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

anesthetic
the medication used to induce anesthesia

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

anticonvulsant
administered to prevent seizures such as those associated with epilepsy

antidepressant
a medication administered to prevent or relieve depression

antipsychotic drug
a medication administered to treat symptoms of severe disorders of thinking and mood that are associated with neurological and psychiatric illnesses such as schizophrenia, mania, and delusional disorders

anxiety disorders
mental conditions characterized by anxiety or fear that is out of proportion to the real danger in a situation

anxiolytic drug
a medication administered to temporarily relieve anxiety and to reduce tension; also known as an antianxiety drug or tranquilizer

aphasia
the loss of the ability to speak, write, and/or comprehend the written or spoken word

arachnoid membrane
the second layer of the meninges and is located between the dura mater and the pia mater

arachnophobia
an excessive fear of spiders

ascending nerve tracts
carry nerve impulses toward the brain

attention deficit disorder
characterized by a short attention span and impulsive behavior that is inappropriate for the child’s developmental age

autism
describes a group of conditions in which a young child cannot develop normal social relationships

autonomic nervous sytem
controls the involuntary actions of the body

axon
a process that extends away from the cell body and conducts impulses away from the nerve cell

barbiturates
a class of drugs whose major action is a calming or depressed effect on the central nervous system

behavioral therapy
focuses on changing behavior by identifying problem behaviors, replacing them with appropriate behaviors, and using rewards or other consequences to make the changes

Bell’s palsy
temporary paralysis of the seventh cranial nerve that causes drooping only on the affected side of the face

bipolar disorder
a condition characterized by cycles of severe mood changes shifting from highs (manic behavior) and severe lows (depression) that affect a person’s attitude, energy, and ability to function

brain tumor
an abnormal growth located inside the skull

brainstem
the stalk-like portion of the brain that connects the cerebral hemispheres with the spinal cord; made up of three parts: the midbrain, pons, and medulla

carotid ultrasonography
an ultrasound study of the carotid artery to detect plaque buildup in the artery to predict or diagnose an ischemic stroke

catatonic behavior
marked by a lack of responsiveness, stupor, and a tendency to remain in a fixed posture

causalgia
persistent, severe burning pain that usually follows an injury to a sensory nerve

central nervous system (CNS)
includes the brain and spinal cord

cephalalgia
pain in the head; also known as a headache

cerebellum
the second-largest part of the brain, located at the back of the head below the posterior portion of the cerebrum

cerebral
pertaining to the cerebrum or to the brain

cerebral contusion
the bruising of brain tissue as the result of a head injury that may also cause swelling of the brain

cerebral hemispheres
the cerebrum is divided into these two parts

cerebral lobes
each cerebral hemisphere is subdivided to create pairs of lobes; each lobe is named for the bone of the cranium that covers it

cerebral palsy
a congenital condition characterized by poor muscle control, spasticity, speech defects, and other neurologic deficiencies

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

cerebrovascular accident
damage to the brain that occurs when the blood flow to the brain is disrupted; also known as a stroke

cerebrum
the largest and uppermost portion of the brain, consisting of four lobes

cervical radiculopathy
nerve pain caused by pressure on the spinal nerve roots in the neck region

claustrophobia
an abnormal fear of being in narrow or enclosed spaces

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

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

cognitive therapy
focuses on changing cognitions or thoughts that are affecting a person’s emotions or actions

coma
a deep state of unconsciousness

complex regional pain syndrome
pain that occurs after an injury to an arm or a leg, a heart attack, stroke, or other medical problem

concussion
a violent shaking up or jarring of the brain that may result in a temporary loss of awareness and function

connecting neurons
associative neurons which link sensory and motor neurons

conscious
the state of being awake, alert, aware, and responding appropriately

conversion disorder
characterized by serious temporary or ongoing changes in function, such as paralysis or blindness, that are triggered by psychological factors rather than by any physical cause

cranial hematoma
a collection of blood trapped in the tissues of the brain

cranial nerves
12 pairs of nerves that originate from the undersurface of the brain

delirium
a potentially reversible condition that comes on suddenly and is often associated with high fever, intoxication, or shock in which the patient is confused, disoriented, and unable to think clearly

delirium tremens
an acute organic brain syndrome due to alcohol withdrawal that is characterized by sweating, tremor, restlessness, anxiety, mental confusion, and hallucinations

delusion
a false personal belief that is maintained despite obvious proof or evidence to the contrary

dementia
a slowly progressive decline in mental abilities, including memory, thinking, and judgment, that is often accompanied by personality changes

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

depression
a common mood disorder characterized by lethargy and sadness, as well as the loss of interest or pleasure in normal activities

descending nerve tracts
carry nerve impulses away from the brain

dissociative disorders
occur when normal thought is separated from consciousness

dissociative identity disorder
a mental illness characterized by the presence of two or more distinct personalities, each with its own characteristics, which appear to exist within the same individual; formerly known as multiple personality disorder

dura mater
the thick, tough, outermost membrane of the meninges

dyslexia
a learning disability characterized by substandard reading achievement due to the inability of the brain to process symbols; also known as a developmental reading disorder

dysthymia
a low-grade chronic depression with symptoms that are milder than those of severe depression but are present on a majority of days for 2 or more years

echoencephalography
the use ofultrasound imaging to diagnose a shift in the midline structures of the brain

efferent neurons (efferent means away from)
motor neurons which carry impulses away from the brain and spinal cord and toward the muscles and glands

electroencephalography
the process of recording the electrical activity of the brain through the use of electrodes attached to the scalp

encephalitis
an inflammation of the brain

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

epidural anesthesia
regional anesthesia produced by injecting a local anesthetic into the epidural space of the lumbar or sacral region of the spine

epilepsy
a chronic neurological condition characterized by recurrent episodes of seizures of varying severity

factitious disorder
a condition in which an individual acts as if he or she has a physical or mental illness when he or she is not really sick; previously known as Munchausen syndrome

factitious disorder by proxy
a form of child abuse; although seeming very concerned about the child’s well-being, the mentally ill parent will falsify an illness in a child by making up, or inducing symptoms, and then seeking medical treatment, even surgery, for the child

ganglion
a nerve center made up of a cluster of nerve cell bodies outside the central nervous system

generalized anxiety disorder
characterized by chronic anxiety plus exaggerated worry and tension even when there is little or nothing to provoke these feelings

glial cells
provide support and protection for neurons

Gullain-Barre syndrome
an inflammation of the myelin sheath of peripheral nerves, characterized by rapidly worsening muscle weakness that may lead to temporary paralysis; also known as infectious polyneuritis

hallucination
a sensory perception experienced in the absence of an external stimulation

hemorrhagic stroke
occurs when a blood vessel in the brain leaks or ruptures; also known as a bleed

hydrocephalus
a condition in which there is an abnormally increased amount of cerebrospinal fluid within the ventricles of the brain

hyperesthesia
a condition of excessive sensitivity to stimuli

hypnotherapy
the use of hypnosis to produce a relaxed state of focused attention in which the patient may be more willing to believe and act on suggestions

hypnotic
depresses the central nervous system and usually produces sleep

hypochondriasis
a condition characterized by misinterpretation of physical symptoms and fearing that one has a serious illness despite appropriate medical evaluation and reassurance

hypothalamus
located below the thalamus, controls vital bodily functions

impulse-control disorders
a group of psychiatric disorders characterized by the inability to resist an impulse despite potential negative consequences

innervations
the supply of nerves to a specific body part

insomnia
the prolonged or abnormal inability to sleep

intracranial pressure
the amount of pressure inside the skull

ischemic stroke
a type of stroke that occurs when the flow of blood to the brain is blocked

kleptomania
a disorder characterized by repeatedly stealing objects neither for personal use nor for their monetary value

learning disabilities
disorders found in children of normal intelligence who have difficulties in learning specific skills such as processing language or grasping mathematical concepts

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

levels of consciousness (LOC)
terms used to describe alterations of consciousness caused by injury, disease, or substances such as medication, drugs, or alcohol

lobectomy
surgical removal of a portion of the brain to treat brain cancer or seizure disorders that cannot be controlled with medication

lumbar puncture
the process of obtaining a sample of cerebrospinal fluid by inserting a needle into the subarachnoid space of the lumbar region to withdraw fluid

lumbar radiculopathy
nerve pain in the lower back caused by muscle spasms or by nerve root irritation from the compression of vertebral disks such as a herniated disk

magnetic resonance imaging (MRI) and computer tomography (CT)
important neuroimaging tools because they facilitate the examination of the soft tissue structures of the brain and spinal cord

malingering
characterized by the intentional creation of false or grossly exaggerated physical or psychological symptoms

manic behavior
includes an abnormally elevated mood state, including inappropriate elation, increased irritability, severe insomnia, poor judgment, and inappropriate social behavior

medulla
located at the lowest part of the brainstem, connected to the spinal cord

meninges
the system of membranes that enclose the brain and spinal cord of the CNS

meningitis
an inflammation of the meninges of the brain or spinal cord

meningocele
the congenital herniation of the meninges that surround the brain or spinal cord through a defect in the skull or spinal column

mental retardation
a diagnosis based on three criteria: 1) significant below-average intellectual functioning; 2) significant deficits in adaptive functioning; and 3) onset during the developmental period of life, which is before age 18

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

migraine headache
a headache characterized by throbbing pain on one side of the head

mood stabilizing drugs
used to treat mood instability and bipolar disorders; an example is lithium

multiple sclerosis
a progressive autoimmune disorder characterized by scattered patches of demyelination of nerve fibers of the brain and spinal cord

myelin sheath
the protective covering made up of glial cells

myelitis
an inflammation of the spinal cord; also inflammation of bone marrow

myelography
a radiographic study of the spinal cord after the injection of a contrast medium through a lumbar puncture. The resulting record is called a myelogram.

myelosis
a tumor of the spinal cord

narcolepsy
a sleep disorder consisting of recurring episodes of falling asleep during the day

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

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

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

neuroplasty
the surgical repair of a nerve or nerves

neurorrhaphy
surgically suturing together the ends of a severed nerve

neurosurgeon
a physician who specializes in surgery of the nervous system

neurotomy
a surgical incision or the dissection of a nerve

neurotransmitters
chemical substances that make it possible for messages to cross from the synapse of a neuron to the target receptor; examples include acetylcholine, dopamine, endorphins, norepinephrine, and serotonin

obsessive-compulsive disorder
an anxiety disorder characterized by recurrent, unwanted thoughts or impulses

panic attack
a group of intense emotional feelings that include apprehension, fearfulness, and terror

panic disorder
an anxiety disorder characterized by unexpected and repeated episodes known as panic attacks

parasympathetic nervous system
returns the body to normal after a response to stress

paresthesia
refers to a burning or prickling sensation that is usually felt in the hands, arms, legs, or feet, but can also occur in other parts of the body

Parkinson’s disease (PD)
a chronic, degenerative central nervous disorder in which there is a progressive loss of control over movement, resulting in tremors and a shuffling gait

peripheral nervous system (PNS)
includes the 12 pairs of cranial nerves extending from the brain and the 31 pairs of peripheral spinal nerves extending outward from the spinal cord

peripheral neuropathy
a painful condition of the nerves of the hands and feet due to damage to the peripheral nerves; also known as peripheral neuritis

peripheralspinal nerves
31 pairs of spinal nerves that are grouped together and named based on the region of the body they innervate

persistent vegetative state
a type of coma in which the patient exhibits alternating sleep and wake cycles

personality disorder
a chronic pattern of inner experience and behavior that causes serious problems with relationships and work

phenobarbital
a barbiturate used as a sedative and as an anticonvulsant

phobia
a persistent irrational fear of a specific thing or situation, strong enough to cause significant distress, to interfere with functioning, and to lead to the avoidance of the thing or situation that causes this reaction

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

plexus
a network of intersecting spinal nerves

poliomyelitis
a highly contagious viral disease; also known as polio

posttraumatic stress disorder (PTSD)
the development of characteristic symptoms after a major traumatic event

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

psychoanalysis
based on the idea that mental disorders have underlying causes stemming from childhood and can only be overcome by gaining insight into one’s feelings and patterns of behavior

psychologist
holds an advanced degree but is not a medical doctor; evaluates and treats emotional problems and mental illness

psychotic disorder
characterized by the loss of contact with reality and deterioration of normal social functioning

psychotropic drug
acts primarily on the central nervous system, where it produces temporary changes affecting the mind, emotions, and behavior

pyromania
a disorder characterized by repeated, deliberate fire setting

radiculitis
an inflammation of the root of a spinal nerve that causes pain and numbness radiating down the affected limb; also known as a pinched nerve

receptors
sites in the sensory organs that receive external stimulation

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

restless legs syndrome (RLS)
a neurological disorder characterized by uncomfortable feelings in the legs, producing a strong urge to move them

Reye’s syndrome (RS)
a potentially fatal condition that has been linked to giving aspirin to children suffering from viral infections

SAM
neuron functions: Sensory neurons (afferent); Associative neurons (connecting); Motor neurons (efferent)

schizophrenia
a psychotic disorder characterized by two or more of the following: delusions, hallucinations, disorganized speech, disorganized or catatonic behavior, and negative symptoms

sciatica
inflammation of the sciatic nerve

seasonal affective disorder (SAD)
a seasonal bout of depression associated with the decrease in hours of daylight during winter months

sedative
depresses the central nervous system to produce calm and diminished responsiveness without producing sleep

seizure
a sudden surge of electrical activity in the brain that affects how a person feels or acts for a short time

shaken baby syndrome
the results of a child being violently shaken by someone

sleep deprivation
a sufficient lack of restorative sleep over a cumulative period so as to cause physical or psychiatric symptoms and affect routine performance or tasks

somatoform disorder
characterized by physical complaints or concerns about one’s body that are out of proportion to any physical findings or disease

somnambulism
the condition of walking or performing some other activity without awakening; also known as sleepwalking

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

stimulant
works by increasing activity in certain areas of the brain to increase concentration and wakefulness

stimulus
anything that excites (activates) a nerve and causes an impulse

stupor
an unresponsive state from which a person can be aroused only briefly and with vigorous, repeated attempts

substance abuse
the addictive use of tobacco, alcohol, medications, or illegal drugs

sympathetic nervous system
prepares the body for emergencies and stress by increasing the breathing rate, heart rate, and blood flow to muscles

synapse
the space between two neurons or between a neuron and a receptor organ

syncope
the brief loss of consciousness caused by the decreased flow of blood to the brain; also known as fainting

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

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

thalamotomy
a surgical incision into the thalamus

thalamus
located below the cerebrum, produces sensations by relaying impulses to and from the cerebrum and the sense organs of the body

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

transient ischemic attack (TIA)
the temporary interruption in the blood supply to the brain

traumatic brain injury
a blow to the head or a penetrating head injury that damages the brain

trichotillomania
a disorder characterized by the repeated pulling out of one’s own hair

trigeminal neuralgia
a condition characterized by sudden, intense, severe lightning-like pain due to an inflammation of the fifth cranial nerve

unconscious
a state of being unaware and unable to respond to any stimuli including pain