The Language of Medicine - Chapter 10: Nervous System

microscopic fiber leading from the cell body that carries the nervous impulse along a nerve cell

axon

large, interlacing network of nerves

plexus

three protective membranes surrounding the brain and spinal cord

meninges

microscopic branching fiber of a nerve cell that is the first part to receive the nervous impulse

dendrite

outer region of the largest part of the brain; composed of gray matter

cerebral cortex

glial cell that transports water and salts between capillaries and nerve cells

astrocyte

glial cell that produces myelin

oligodendroglial cell

a nerve cell that transmits a nerve impulse

neuron

collection of spinal nerves below the end of the spinal cord at the level of the second lumbar vertebra

cauda equina

fatty tissue that surrounds the axon of a nerve cell

myelin sheath

dura mater

outermost meningeal layer surrounding the brain and spinal cord

central nervous system

brain and the spinal cord

peripheral nervous system

nerves outside the brain and spinal cord; cranial, spinal, and autonomic nerves

arachnoid membrane

middle meningeal membrane surrounding the brain and spinal cord

hypothalamus

part of the brain below the thalamus; controls sleep, appetite, body temperature, and secretions from the pituitary gland

synapse

space through which a nervous impulse is transmitted from a nerve cell to another nerve cell or to a muscle or gland cell

sympathetic nerves

autonomic nerves that influence bodily functions involuntarily in times of stress

medulla oblongata

part of the brain just above the spinal cord that controls breathing, heartbeat, and the size of blood vessels

pons

part of the brain anterior to the cerebellum and between the medulla and upper parts of the brain; connects these parts of the brain

cerebellum

posterior part of the brain that coordinates voluntary muscle movements

thalamus

part of the brain below the cerebrum; relay center that conducts impulses between the spinal cord and the cerebrum

ventricles of the brain

canals in the interior of the brain that are filled with CSF

brainstem

lower portion of the brain that connects the cerebrum with the spinal cord (includes the pons and the medulla)

cerebrum

largest part of the brain; controls voluntary muscle movement, vision, speech, hearing, thought, memory

ganglion

collection of nerve cell bodies outside the brain and spinal cord

innermost meningeal membrane

pia mater

carry messages away from (efferent) the brain and spinal cord to muscles and glands

motor nerves

carry messages toward (afferent) the brain and spinal cord from receptors

sensory nerves

grooves in the cerebral cortex

sulci

contains cerebrospinal fluid

subarachnoid space

elevations in the cerebral cortex

gyri

chemical that is released at the end of a nerve cell and stimulates or inhibits another cell (example: acetylcholine)

neurotransmitter

essential cell of the nervous system; a neuron

parenchymal cell

connective and supportive (stromal) tissue

glial cells

disease of the brain

encephalopathy

part of the brain that controls muscular coordination and balance

cerebellum

collection of blood above the dura mater

epidural hematoma

inflammation of the pia and arachnoid membranes

leptomeningitis

condition of absence of a brain

anencephaly

inflammation of the gray matter of the spinal cord

poliomyelitis

pertaining to the membranes around the brain and spinal cord

meningeal

disease of nerve roots (of spinal nerves)

radiculopathy

hernia of the spinal cord and meninges

myelomeningocele

pertaining to the tenth cranial nerve

vagal

cerebral cortex

outer region of the cerebrum (contains gray matter)

intrathecal

pertaining to within a sheath through the meninges and into the subarachnoid space

polyneuritis

inflammation of many nerves

thalamic

pertaining to the thalamus

myelopathy

disease of the spinal cord

meningloma

tumor of the meninges

glioma

tumor of neuroglial cells (a brain tumor)

subdural hematoma

mass of blood below the dura mater (outermost meningeal membrane)

reading disorder

dyslexia

condition of decreased coordination

ataxia

condition of slow movement

bradykinesia

condition of increased sensation

hyperesthesia

seizure of sleep; uncontrollable compulsion to sleep

narcolepsy

difficulty with speech

aphasia

inability to perform a task

motor apraxia

weakness in the right or left half of the body

hemiparesis

severe burning pain due to nerve injury

causalgia

paralysis in the lower part of the body

paraplegia

fainting

syncope

nervous exhaustion (lack of strength) and fatigue

neurasthenia

analgesia

lack of sensitivity to pain

motor aphasia

difficulty in speaking (patient cannot articulate words but can understand speech and knows that she or he wants to say)

paresis

weakness and partial loss of movement

quadriplegia

paralysis in all four extremities (damage is to the cervical part of the spinal cord)

asthenia

no strength (weakness)

comatose

pertaining to coma (loss of consciousness from which the patient cannot be aroused)

paresthesia

condition of abnormal sensations (prickling, tingling, burning)

hyperkinesis

excessive movement

anesthesia

condition of no sensation or nervous feeling

causalgia

severe burning pain from injury to peripheral nerves

akinetic

pertaining to without movement

hypalgesia

diminished sensation to pain

dyskinesia

impairment of the ability to perform voluntary movements

migraine

recurrent vascular headache with severe pain of unilateral onset and photophobia (sensitivity to light)

Destruction of myelin sheath (demyelination) and its replacement by hard plaques:

multiple sclerosis

Sudden, transient disturbances of brain function cause seizures:

epilepsy

The spinal column is imperfectly joined (a split in a vertebra occurs), and part of the meninges and spinal cord can herniate out of the spinal cavity:

myelomeningocele

Atrophy of muscles and paralysis caused by damage to motor neurons in the spinal cord and brainstem:

amyotrophic lateral sclerosis

Patient displays bizarre, abrupt, involuntary, dance-like movements, as well as decline in mental functions:

Huntington disease

Cerebrospinal fluid accumulates in the head (in ventricles of the brain):

hydrocephalus

loss of muscle strength due to the inability of a neurotransmitter (acetylcholine) to transmit impulses from nerve cells to muscle cells:

myasthenia gravis

Degeneration of nerves in the basal ganglia occurring in later life, leading to tremors, shuffling gait, and muscle stiffness; dopamine (neurotransmitter) is deficient in the brain:

Parkinson disease

Deterioration of mental capacity (dementia); autopsy shows cerebral cortex atrophy, widening of cerebral sulci, and microscopic neurofibrillary tangled:

Alzheimer disease

Unilateral facial paralysis:

Bell palsy

astrocytoma

tumor of neuroglial brain cells (astrocytes)

pyogenic meningitis

inflammation of the meninges (bacterial infection with pus formation)

Tourette syndrome

involuntary, spasmodic, twitching movements (tics), uncontrollable vocal sounds, and inappropriate words

cerebral contusion

bruising of brain tissue as the result of direct trauma to the head

cerebrovascular accident

disruption of the normal blood supply to the brain; stroke or cerebral infarction

cerebral concussion

traumatic brain injury caused by a blow to the head

herpes zoster

neurologic condition caused by infection with the herpes zoster virus; blisters form along the course of peripheral nerves

cerebral embolus

blockage of a blood vessel in the cerebrum caused by material from another part of the body that suddenly occludes the vessel

cerebral thrombosis

blockage of a blood vessel in the cerebrum caused by the formation of a clot within the vessel

cerebral hemorrhage

collection of blood in the brain (can cause a stroke)

cerebral aneurysm

widening of a blood vessel (artery) in the cerebrum; the aneurysm can burst and lead to a CVA

HIV encephalopathy

brain disease (dementia and encephalitis) caused by infection with AIDS virus