Ch. 10 - Nervous system

absence seizure

minor form of seizure, consisting of momentary clouding of consciousness and loss of contact with the environment; petit mal seizure

acetylcholine

neurotransmitter chemical released at the ends of nerve cells

afferent nerves

carry nervous impulses toward the brain and spinal cord; sensory nerves

akinetic

pertaining to loss or absence of voluntary movement

Alzheimer disease

brain disorder marked by progressive, gradual mental deterioration (dementia) along with personality changes and impairment of daily functioning

analgesia

absence of sensitivity to pain

anencephaly

congenital condition of partial or complete absence of brain matter

anesthesia

absence of nervous feeling or sensation

aneurysm

weakening of an arterial wall, which may lead to hemorrhage and cerebrovascular accident

aphasia

inability to speak; language function is impaired due to injury to the cerebral cortex

apraxia

inability to perform purposeful acts or manipulate objects

arachnoid membrane

middle layer of the meninges that surround the brain and spinal cord

astrocyte

glial (neuroglial) cell that transports salts and water from capillaries

astrocytoma

brain tumor composed of astrocytes (glial cells). the most serious of these tumors is a glioblastoma multiforme (Grades III and IV malignant brain tumor)

ataxia

without coordination

aura

peculiar sensation appearing before more definite symptoms

autonomic nervous system

nerves that control involuntary body functions of muscles, glands, and internal organs

axon

microscopic fiber that carries a nervous impulse along a nerve cell

Bell palsy

unilateral paralysis of the face caused by a disorder of the facial nerve

blood-brain barrier

blood vessels that let certain substances enter the brain tissue and keep other substances out

bradykinesia

slow movement

brainstem

lower portion of the brain that connects the cerebrum with the spinal cord

cauda equina

collection of spinal nerves below the end of the spinal cord

causalgia

intense burning pain, often resulting from injury to a peripheral nerve

cell body

part of the nerve cell (neuron) that contains the nucleus

central nervous system

brain and spinal cord

cephalgia

head pain; headache

cerebellar

pertaining to the cerebellum

cerebellopontine

pertaining to the cerebellum and pons

cerebellum

part of the brain that coordinates muscle movements and maintains balance

cerebral angiography

x-ray record of blood vessels in the brain after intravenous injection of contrast material

cerebral concussion

temporary brain dysfunction (brief loss of consciousness) after injury; usually clearing within 24 hours

cerebral contusion

bruising of brain tissue as a result of direct trauma to the head; neurologic disorder persists longer than 24 hours

cerebral cortex

outer region of the cerebrum

cerebral hemorrhage

bursting of an artery in the brain

cerebral palsy

partial paralysis and muscular coordination caused by loss of oxygen or blood flow to the cerebrum during pregnancy or in the perinatal period

cerebrospinal fluid

clear, watery fluid that circulates throughout the brain and spinal cord

cerebrospinal fluid analysis

samples of cerebrospinal fluid are examined for blood cells, protein, glucose, tumor cells, bacteria and other substances

cerebrovascular accident (CVA)

disruption of the normal blood supply to the brain; stroke

cerebrum

largest part of the brain; responsible for voluntary muscular activity, vision, speech, taste, hearing, thought and memory, among other functions

coma

state of unconsciousness from which a patient cannot be aroused

comatose

pertaining to a coma

computed tomography

cross-sectional x-ray imaging of an organ (such as the brain or spinal cord), with or without contrast material

cranial nerves

twelve pairs of nerves that carry messages to and from the brain

dementia

mental decline and deterioration

demyelination

destruction of myelin on axons of nerves (as in multiple sclerosis)

dendrite

microscopic branching portion of a nerve cell; first part of the nerve cell to receive the nervous impulse

dopamine

neurotransmitter in the central nervous system; deficient in patients with Parkinson disease

doppler/ultrasound studies

sound waves are used to detect blood flow in arteries within the brain and leading to the brain

dura mater

thick, outermost layer of the meninges surrounding the brain and spinal cord

dyskinesia

impairment of the ability to perform voluntary movements

dyslexia

difficulty in reading, writing, and learning

efferent nerves

carry messages away from the brain to the spinal cord; motor nerves

electroencephalography

process of recording the electricity in the brain

embolus

blood clot that is carried by the bloodstream from one area of the body to another where it blocks a blood vessel

encephalitis

inflammation of the brain

encephalopathy

disease of the brain

ependymal cell

a glial cell that lines the membranes within the brain and spinal cord and helps form cerebrospinal fluid

epidural hematoma

collection of blood located above the dura mater

epilepsy

brain disorder marked by recurrent attacks (seizures) of abnormal nervous impulses

gait

manner of walking

ganglion

collection of nerve cell bodies in the peripheral nervous system

glial cell

nervous system cell that is supportive and connective in function: astrocyte, microglial cell, and ependymal cell

glioblastoma

rapidly growing malignant tumor of the brain

gyrus; gyri

sheet of nerve cells that produces a rounded fold on the surface of the cerebrum

hemiparesis

slight paralysis of the right or left half of the body

hemiplegia

paralysis of the right or left half of the body

herpes zoster

viral infection affecting peripheral nerves

HIV encephalopathy

disease of the brain (dementia) caused by infection with the human immunodeficiency virus, which causes AIDS

Huntington disease

hereditary disorder affecting the cerebrum and involving abrupt, involuntary, jerking movements, and mental deterioration in later stages

hydrocephalus

abnormal accumulation of cerebrospinal fluid in the ventricles (canals) of the brain

hypalgesia

diminished sensitivity to pain

hyperesthesia

excessive sensitivity or feeling, especially of the skin in response to touch or pain

hyperkinesis

excessive movement

hypothalamus

region of the brain lying below the thalamus, but above the pituitary gland. it stimulates the pituitary gland to secrete and release hormones

ictal event

pertaining to a sudden, acute onset, as the convulsion of an epileptic seizure

intrathecal

pertaining to within the membranes (meninges) surrounding the brain and spinal cord

leptomeningitis

inflammation of the two thinner membranes (arachnoid and pia mater) surrounding the brain and spinal cord

lumbar puncture

withdrawal of cerebrospinal fluid from the subarachnoid space between two lumbar vertebrae; spinal tap

magnetic resonance imaging

magnetic waves and radio waves are used to produce images of organs and tissues in all three planes of the body

medulla oblongata

lower part of the brain, closest to the spinal cord; controls breathing, heartbeat, and size of blood vessels

meningeal

pertaining to the meninges

meninges

three membranes surrounding and protecting the brain and spinal cord

meningioma

tumor (benign) of the meninges

meningitis

inflammation of the meninges

meningocele

hernia of the meninges through a defect or space between vertebrae; a form of spina bifida cystica

microglial cell

phagocystic glial cell that removes waste products from the central nervous system

midbrain

the uppermost portion of the brainstem. it contains pathways connecting the cerebrum with lower portions of the brain and structures involved with seeing and hearing.

migraine

a severe headache, often unilateral, and sometimes accompanied by nausea and vomiting

motor nerves

carry impulses from the brain and spinal cord to muscles

multiple sclerosis

chronic neurologic disorder marked by destruction of the myelin sheath on neuronal axons in the CNS and replacement by plaques of sclerotic tissue

myasthenia gravis

autoimmune neuromuscular disorder characterized by weakness of voluntary muscles

myelin sheath

fatty, white covering over the axon of a nerve cell

myelomeningocele

congenital hernia (protrusion) of the spinal cord and meninges through a defect (gap) in the vertebral column. this defect is often associated with spina bifida.

myoneural

pertaining to muscle and nerve

narcolepsy

sudden seizures of sleep

nerve

macroscopic cordlike collection of fibers that carry electrical impulses

neuralgia

nerve pain

neurasthenia

lack of strength in nerves; a feeling of weakness and exhaustion.

neuroglia

supporting cells (stroma) of the nervous system; glial cells