Nervous System Flashcards
absence seizure
a small seizure in which there is a sudden or temporary loss of consciousness lasting only a few seconds
acetylcholine
a chemical substance in the body tissues that facilitates the transmission of nerve impulses from one nerve to another. It has a stimulant effect on some parts of the body and a depressant effect on other parts of the body; also known as a neurotransmitter.
afferent nerves
transmitters of nerve impulses toward the CNS; also known as sensory nerves
agnosia
loss of mental ability to understand sensory stimuli (such as sound, sight, touch) even though the sensory organs themselves are functioning properly
agraphia
the inability to convert one’s thoughts into writing
alexia
the inability to understand written words
analgesia
without sensitivity to pain
anesthesia
without feeling or sensation
aneurysm
a localized dilatation in the wall of an artery that expands with each pulsation of the artery; usually caused by hypertension or artherosclerosis
aphasia
inability to communicate through speech, writing or signs because of an injury or disease in certain areas of the brain.
apraxia
inability to perform coordinated movements or use objects properly; not associated with sensory or motor impairment or paralysis
arachnoid membrane
the weblike middle layer of the three membranous layers surrounding the brain and spinal cord.
astrocyte
a star-shaped neuroglial cell found in the the CNS
astrocytoma
a tumor of the brain or spinal cord composed of astrocytes
ataxia
without muscular coordination
aura
the sensation an individual experiences prior to the onset of migraine headache or an epileptic seizure. It may be a sensation of light or warmth and may precede the attack by hours or only a few seconds
autonomic nervous system
the part f the nervous system that regulates the involuntary vital functions of the body, such as the activities involving the heart muscle, smooth muscles, and the glands. Has two divisions: the SNS and the PNS.
axon
the part of the nerve cell that transports nerve impulses away from the nerve cell body
blood-brain barrier
a protective characteristic of the capillary walls o the brain that prevents the passage of harmful substances from the bloodstream into the brain tissue of CSF.
bradykinesia
Abnormally slow movement
brain stem
the stemlike portion of the brain that connects the cerebral hemisphere with the spinal cord. It contains the midbrain, the pons, and the medulla oblongata.
Brudzinski’s sign
a positive sign of meningitis, in which there is an involuntary flexion of the arm, hip and knee when the patient’s neck is passively flexed
burr hole
a hole drilled into the skull using a form of drill
cauda equina
the lower end of the spinal cord and the roots of the spinal nerves that occupy the spinal canal below the level of the first lumbar vertebra; so named because it resembles a horse’s tail
causalgia
a sensation of an acute burning pain along the path of a peripheral nerve, sometimes accompanied by erythema of the skin; due to injury to peripheral nerve fibers.
cell body
the part of the cell that contains the nucleus and the cytoplasm
central nervous system
one of the two main divisions of the nervous system, consisting of the brain and the spinal cord.
cephalagia
pain in the head; headache
cerebellum
the part of the brain responsible for coordinating voluntary muscular movement; located behind the brain stem.
cerebral concussion
a brief interruption of brain function, usually with a loss of consciousness lasting for a few seconds. This transient loss of consciousness is usually caused by blunt trauma (a blow to the head)
cerebral contusion
small scattered venous hemorrhages in the brain; better described as a “bruise” of the brain tissue occurring when the brain strikes the inner skull
cerebral cortex
the thin outer layer of nerve tissue, known as gray matter, that covers the surface of the cerebrum
cerebrospinal fluid
the fluid flowing through the brain and around the spinal cord that protects them from physical blow or impact.
cerebrum
the largest and uppermost part of the brain. It controls consciousness, memory, sensations, emotions and voluntary movements.
Cheyne-Stokes respirations
an abnormal pattern of breathing characterized by periods of apnea followed by deep rapid breathing
coma
a deep sleep in which the individual cannot be aroused and does not respond to external stimuli.
comatose
pertains to being in a coma
contracture
a permanent shortening of a muscle causing a joint to remain in an abnormally flexed position, with resultant physical deformity.
convolution
one of the many elevated folds of the surface of the cerebrum; also call gyrus.
craniotomy
a surgical incision into the cranium or skull
deficit
any deficiency or variation of the normal, as in weakness deficit resulting from a cerebrovascular accident (CVA)
dementia
a progressive irreversible mental disorder in which the person has deteriorating memory, judgment and ability to think
demyelination
destruction or removal of the myelin sheath that covers a nerve or nerve fiber.
dendrite
a projection that extends from the nerve cell body. It receives impulses and conducts them on the cell body.
diencephalon
the part of the brain located between the cerebrum and the midbrain. Its main structures consist of the thalamus, hypothalamus
diplopia
double vision; also called ambiopia
dura mater
the outermost of the three membranes (meninges) surrounding the brain and spinal cord
dyslexia
a condition characterized by an impairment of the ability to read. Letters and words are often reversed when reading.
dysphasia
difficult speech
efferent nerves
transmitters of nerve impulses away from the CNS; also known as motor nerves
embolism
an abnormal condition in which a blood clot (embolus) becomes lodged in a blood vessel, obstructing the flow of blood within the vessel.
epidural space
the space immediately outside the dura mater that contains a supporting cushion of fat and other connective tissues.
epilepsy
a neurological condition characterized by recurrent episodes of sudden brief attacks of seizures. The seizure may vary from mild and unnoticeable to full-scale convulsive seizures.
fissure
a deep groove on the surface of an organ
fontanelle or fontanel
a space covered by tough membrane between the bones of an infant’s cranium, called a “soft spot”.
gait
the style of walking
ganglion
a knotlike mass of nerve tissue found outside the brain or spinal cord (plural: ganglia)
gray matter
the part of the nervous system consisting of axons that are not convered with myelin sheath, giving a gray appearance.
gyrus
one of the many elevated folds of the surface of the cerebrum (plural: gyri).
hemiparesis
slight or partial paralysis of one half of the body
hemiplegia
paralysis of one half of the boy
herpes zoster
an acute infection caused by the same virus that causes chickenpox, characterized by painful vesicular lesions along the path of a spinal nerve; also called shingles
hyperesthesia
excessive sensitivity to sensory stimuli, such as pain or touch
hyperkinesis
excessive muscular movement and physical activity; hyperactivity.
hypothalamus
a part of the brain located below the thalamus that controls many functions, such as body temperature, sleep and appetite.
interneurons
connecting neurons that conduct impulses from afferent nerves to or toward motor nerves
kernig’s sign
a diagnostic sign for meningitis marked by the person’s inability to extend the leg completely when the thigh is flexed upon the abdomen and the person is sitting or lying down.
kinesiology
the study of muscle movement
lethargy
a state of being sluggish
longitudinal fissure
a deep groove in the middle of the cerebrum that divides the cerebrum into the right and left hemisphere.
medulla oblongata
one of the three parts of the brain stem. It is the most essential part f the brain in that it contains the cardiac, vasomotor, and respiratory centers in the brain.
meninges
the three layers of protective membranes that surround the brain and spinal cord.
microglia
small neuroglial cells found in the interstitial tissue of the nervous system that engulf cellular debris, waste products, and pathogens withing the nerve tissue.
midbrain
the uppermost part of the brain stem.
motor nerves
Transmitters of nerve impulses away from the CNS; also known as efferent nerves
myelin sheath
a protective sheath that covers the axons of many nerves in the body. It acts as an electrical insulator and helps to speed the conduction of nerve impulses.
narcolepsy
a rare syndrome of uncontrolled, sudden attacks of sleep.
nerve
a cordlike bundle of nerve fibers that transmit impulses to and from the brain and spinal cord to other parts of the body. It is macroscopic.
nerve block
the injection of a local anesthetic along the course of a nerve or nerves to eliminate sensation to the area supplied by the nerve(s); also called conduction anesthesia.
neuralgia
Severe, sharp, spasmlike pain that extends along the course of one or more nerves.
neuritis
Inflammation of a nerve
neuroglia
the supporting tissue of the nervous system
neurologist
a physician who specializes in treating the diseases and disorders of the nervous system.
neurology
the study of the nervous system and its disorders
neuron
a nerve cell
neurosurgeon
a physician who specializes in surgery of the nervous system.
neurosurgery
any surgery involving the nervous system (i.e., of the brain, spinal cord, or peripheral nerves).
neurotransmitter
a chemical substance within the body that activates or inhibits the transmission of nerve impulses at synapses.
nuchal rigidity
rigidity of the neck. The neck is resistant to flexion. This condition is seen with patients with meningitis
occlusion
blockage
oligodendrocyte
a type of neurogial cell found in the interstitial tissue of the nervous system. Its dendrite projections coil around the axons of many neurons to form the myelin sheath.
palliative
soothing
paraplegia
paralysis of the lower extremities and trunk, usually due to spinal cord injuries
parasympathetic nerves
nerves of the ANS that regulate essential involuntary body functions such as slowing the heart rate, increasing peristalsis of the intestines, increasing glandular secretions, and relaxing sphincters.
parasympathomimetic
copying or producing the same effects as those o the parasympathetic nerves; “to mimic” the parasympathetic nerves
paresthesia
a sensation of numbness or tingling
peripheral nervous system
the part of the nervous system outside the CNS, consisting of 12 pairs of cranial nerves and 31 pairs of spinal nerves.
phagocytosis
the process by which certain cells engulf and destroy microorganisms and cellular debris.
pia mater
the innermost of the three membranes (meninges) surrounding the brain and spinal cord
pineal body
a small cone-shaped structure (located in the diencephalon of the brain) thought to be involved in regulating the body’s biological clock and that produces melatonin; also called the pineal gland
pineal gland
a small cone-shaped structure (located in the diencephalon of the brain) thought to be involved in regulating the body’s biological clock and that produces melatonin; also called the pineal body
plexus
a network of interwoven nerves
pons
the part of the brain located between the medulla oblongata and the midbrain. t acts as a bridge to connect the medulla oblongata and the cerebellum to the upper portions of the brain.
quadriplegia
paralysis of all four exremities and the trunk of the body; caused by injury to the spinal cord at the level of the cervical vertebrae
radiculotomy
the surgical resection of a spinal nerve root (a procedure performed to relieve pain); also called a rhizotomy
receptor
a sensory nerve ending (i.e., a nerve ending that receives impulses and responds to various types of stimulation).
rhizotomy
the surgical resection of a spinal nerve root (a procedure performed to relieve pain); also called a radiculotomy
sciatica
inflammation of the sciatic nerve; characterized by pain along the course of the nerve, radiating through the thigh and down the back of the leg
sensory
pertaining to sensation
sensory nerves
transmitters of nerve impulses toward the CNS; also known as afferent nerves
shingles
an acute infection caused by the same virus that causes chickenpox, characterized by painful vesicular lesions along the path of a spinal nerve; also called herpes zoster
shunt
a tube or passage that diverts or redirects body fluid from one cavity or vessel to another; may be a congenital defect or artificially constructed for the purpose of redirecting fluid
somatic nervous system
the part of the PNS that provides voluntary control over skeletal muscle contractions
stimulus
any agent or factor capable of initiating a nerve impulse
stupor
a state of lethargy. the person is unresponsive and seems unaware of his/her surroundings
subarachnoid space
the space located just under the arachnoid membrane that contains cerebrospinal fluid
subdural space
the space located just beneath the dura mater that contains serous fluid.
sulcus
a depression or shallow groove on the surface of an organ
sympathetic nerves
nerves of the ANS that regulate essential involuntary body functions such as increasing the heart rate, constricting blood vessels, and raising the blood pressure.
sympathomimetic
copying or producing the same effects as those of the sympathetic nerves; “to mimic” the sympathetic nerves
synapse
the space between the end of one nerve and the beginning of another, through which nerve impulses are transmitted.
syncope
fainting
thalamus
the part of the brain located between the cerebral hemispheres and the midbrain. The thalamus receives all sensory stimuli, except those of smell and relays them to the cerebral cortex
thrombosis
an abnormal condition in which a clot develops in a blood vessel
tonic-clonic seizure
a seizure characterized by the presence of muscle contraction or tension followed by relaxation, creating a “jerking” movement of the body.
ventricle
a small hollow within the brain that is filled with cerebrospinal fluid
whiplash
an injury to the cervical vertebrae and their supporting structures due to a sudden back-and-forth jerking movement of the head and neck.
white matter
the part of the nervous system consisting of axons covered with myelin sheath, giving a white appearance.
Alzheimer’s disease
deterioration of a person’s intellectual functioning. It is progressive and extremely debilitating. It begins with minor memory loss and progresses to complete loss of mental, emotional, and physical functioning, frequently occurring in persons over 65 years of age.
amyotrophic leteral sclerosis
a severe weakening and wasting of the involved muscle groups, usually beginning with the hands and progressing to the shoulders, upper arms, and legs. It is caused by decreased nerve innervation to the muscle groups
.anencephaly
is an absence of the brain and spinal cord at birth, a congenital disorder
Bell’s palsy
a temporary or permanent unilateral weakness or paralysis of the muscles in the face following trauma to the face, an unknown infection, or a tumor pressing on the facial nerve rendering it paralyzed.
brain abscess
is a localized accumulation of pus located anywhere in the brain tissue due to an infectious process - either a primary local infection or an infection secondary to another infectious process in the body (such as bacterial endocarditis, sinusitis, otitis or dental abscess.
carpal tunnel syndrome
a pinching or compression of the median nerve within the carpal tunnel due to inflammation and swelling to the tendons, causing intermittent or continuous pain that is greatest at night.
cerebral concussion
a brief interruption of brain function, usually with a loss of consciousness lasting for a few seconds.
cerebral contusion
a small, scattered venous hemorrhage in the brain (or better described as a “bruise” of the brain tissue) occurring when the brain strikes the inner skull.
cerebral palsy
a collective term used to describe congenital (at birth) brain damage that is permanent, but not progressive. It is characterized by the child’s lack of control of voluntary muscles.
cerebrovascular accident (CVA)
involves death of a specific portion of brain tissue, resulting from a decrease in blood flow (ischemia) to that area of the brain; also called stroke
degenerative disk
the deterioration of the intervertebral disk, usually due to constant motion and wear on the disk.
encephalitis
the inflammation of the brain or spinal cord tissue largely caused by a virus that enters the CNS when the person experiences a viral disease such as measles or mumps or through the bite of a mosquito or tick
epilepsy
a syndrome of recurring episodes of excessive irregular electrical activity of brain resulting in involuntary muscle movements called seizures.
grand mal seizure
an epileptic seizure characterized by sudden loss of consciousness and by generalized involuntary muscular contraction, vacillating between rigid body extension and an alternating contracting and relaxing of the muscles
petit mal seizure
a small seizure in which there is a sudden temporary loss of consciousness lasting only a few seconds; also known as an absence seizure
Guillain-Barre syndrome
acute polyneuritis (“inflammation of many nerves”) of the PNS in which the myelin sheaths on the axons are destroyed, resulting in decreased nerve impulses, loss of reflex response, and sudden muscle weakness, which usually follows a viral gastrointestinal or respiratory infection
headache
involves pain (varying in intensity from mild to severe) anywhere within the cranial cavity. It may be chronic or acute and may occur as a result of a disease process or e totally benign.
migraine headache
a recurring, pulsating, vascular headache usually developing on one side of the head. It is characterized by a slow onset that my be preceded by an aura, during which a sensory disturbance occurs such as confusion or some visual interference (e.g., flashing lights).
cluster headache
occurs typically two to three hours after falling asleep; described as extreme pain around one eye that wakens the person from sleep.
tension headache
occurs from long, endured contraction of the skeletal muscles around the face, scalp, upper back, and neck.
hematoma, epidural
a collection of blood located above the dura mater and just below the skull
hematoma, subdural
a collection of blood below the dura mater and above the arachnoid layer of the meninges.
herniated disk
a rupture or herniation of the disk center (nucleus pulposus) through the disk wall into the spinal canal, causing pressure on the spinal cord or nerve roots.
Huntington’s chorea
an inherited neurological disease characterized by rapid, jerky, involuntary movements and increasing dementia due to the effects of the basal ganglia on the neurons.
hydrocephalus
an abnormal increase of cerebrospinal fluid in the brain that causes the ventricle of the brain to dilate, resulting in an increased head circumference in the infant with open fontanel(s); a congenital disorder.
metastatic intracranial tumors (secondary)
occur as a result of metastasis from a primary site such as the lung or breast. they occur more frequently than primary neoplasms.
meningitis (acute bacterial)
a serious bacterial infection of the meninges - the covering of the brain and spinal cord - that can have residual debilitating effects or even a fatal outcome if not diagnosed and treated promptly with appropriate antibiotic therapy
multiple sclerosis
a degenerative inflammatory disease of the CNS attacking the myelin sheath in the spinal cord and brain leaving it sclerosed (hardened) or scarred and interrupting the flow of nerve impulses.
myasthenia gravis
a chronic progressive neuromuscular disorder causing severe skeletal mfuscle weakness (without atrophy) and fatigue, which occurs at different levels of severity.
neuroblastoma
a highly malignant tumor of the sympathetic nervous system
Parkinson’s disease
a degenerative, slowly progressive deterioration of nerves in the brain stem’s motor system characterized by a gradual onset of symptoms such as a stooped posture with the body flexed forward; a bowed head; a shuffling gait; pill-rolling gestures; an expressionless, masklike facial appearance; muffled speech; and swallowing difficulty.
peripheral neuritis
a general term indicating inflammation of one or more peripheral nerves, the effects being dependent on the particular nerve involved.
poliomeylitis
an infectious viral disease entering through the upper respiratory tract and affecting the ability of spinal cord and brain motor neurons to receive stimulation. Muscles affected become paralyzed without the motor nerve stimulation (i.e., respiratory paralysis requires ventilatory support.)
pospolio syndrome
progressive weakness occurring at least 30 years after the initial poliomyelitis attack.
Reye’s syndrome
an acute brain encephalopathy along with fatty infiltration of the internal organs that may follow acute viral infections; occurs in children between 5 and 11, often with a fatal result. There are confirmed studies linking the onset of to aspirin administration during a viral illness
shingles
an acute viral infection seen mainly in adults who have had chicken pox, characterized by inflammation of the underlying spinal or cranial nerve pathway (producing painful vesicular eruptions on the skin along these nerve pathways).
skull fracture (depressed)
a broken segment of the skull bone thrust into the brain as a result of a direct force, usually a blunt object
Spina bifida cystica
a congenital defect of the CNS in which the back portion of one or more vertebrae is not closed normally and a cyst protrudes through the opening in the back, usually at the level of the fifth lumbar or first sacral vertebrae.
meningocele
a cystlike sac covered with skin or a thin membrane protruding through the bony defect in the vertebrae containing meninges and CSF
meningomyelocele
a cystlike sac covered with skin or a thin membrane protruding through the bony defect in the vertebrae that contains meninges, CSF and spinal cord segments
spina bifida occulta
a congenital defect of the CNS in which the back portion of one or more vertebrae is not closed. A dimpling over the area may occur.
spinal cord injuries
severe injuries to the spinal cord, such as vertebral dislocation or vertebral fractures, resulting in impairment of spinal cord function below the level of the injury.
paraplegia
(paralysis of the lower extremities) is caused by severe injury to the spinal cord in the thoracic or lumbar region, resulting in loss of sensory and motor control below the level of injury.
quadriplegia
follows severe trauma to the spinal cord between the fifth and seventh cervical vertebrae, generally resulting in loss of motor and sensory function below the level of injury.
Tay-Sachs disease
a congenital disorder caused by altered lipid metabolism, resulting from enzyme deficiency.
trigeminal neuralgia
short periods of severe unilateral pain, which radiates along the fifth cranial nerve
Babinski’s reflex
can be tested by stroking the sole of the foot beginning at midheel and moving upward and lateral t the toes. A positive occurs when there is dorsiflexion of the great toe and fanning of the other toes.
brain scan
a brain scan is a nuclear counter scanning of cranial content two hours after an intravenous injection of radioisotopes
cerebral angiography
visualization of the cerebral vascular system via X-ray after the injection of a radiopaque contrast medium into an arterial blood vessel (carotid, femoral or brachial)
cerebrospinal fluid analysis
CSF obtained from a lumbar puncture is analyzed for the presence of bacteria, blood, or malignant cells as well as for the amount of protein and glucose present
CT of the brain
analysis of a three-dimensional view of brain tissue obtained as X-ray beams pass through successive horizontal layers of the brain
chordotomy
a neurosurgical procedure for pain control accomplished through a laminectomy, in which there is surgical interference of pathways within the spinal cord that control pain.
cisternal puncture
involves insertion of a short, beveled spinal needle into the cisterna magna (a shallow reservoir of CSF between the medulla and the cerebellum) to drain CSF or to obtain a CSF specimen.
craniotomy
a surgical procedure that makes an opening into the skull
echoencephalography
Ultrasound used to analyze the intracranial structures of the brain
electroencephalography (EEG)
measurement of electrical activity produced by the brain and recorded through electrodes place don the scalp
electromyography
is the process of recording the electrical activity of muscle by inserting a small needle into the muscle and delivering a small current that stimulates the muscle
laminectomy
the surgical removal of the bony arches from one or more of the vertebrae to relive pressure on the spinal cord
lumbar puncture
involves the insertion of a hollow needle and stylet into the subarachnoid space, generally between the third and fourth lumbar vertebrae below the level of the spinal cord under strict aseptic technique
magnetic resonance imaging (MRI)
a noninvasive scanning procedure that provides visualization of fluid, soft tissue and bony structures without the use of radiation
myelography
the introduction of contrast medium into the lumbar subarachnoid space through a lumbar puncture to visualize the spinal cord and vertebral canal through X-ray examination.
neurectomy
a neurosurgical procedure to relieve pain in a localized or small area by incision of cranial or peripheral nerves.
pneumoencephalography
used to visualize radiographically one of the ventricles or fluid-occupying spaces in the CNS.
polysomnogram
a sleep study or sleep test that evaluates physical factors affecting sleep. Physical activity and level of sleep are monitored by a technician while the patient sleeps.
positron emission tomography (PET)
scan produces computerized radiographic images of various body structures when radioactive substances are inhaled or injected.
Romberg test
used to evaluate cerebellar function and balance
stereotaxic neurosurgery
performed on a precise location of an area within the brain that controls specific function(s) and may involve destruction of brain tissue with various agents such as heat, cold, and sclerosing or corrosive fluids.
sympathectomy
a surgical procedure used to interrupt a portion of the sympathetic nerve pathway for the purpose of relieving chronic pain
tractotomy
involves a craniotomy, through which the anterolateral pathway in the brain stem is surgically divided in an attempt to relieve pain.
transcutaneous electrical nerve stimulation
a form of cutaneous stimulation for pain relief that supplies electrical impulses to the nerve endings of a nerve close to the pain site.
ACTH
adrenocorticotrophic hormone
ALS
amyotrophic lateral sclerosis
ANS
autonomic nervous system
CAT
computerized axial tomography
CNS
central nervous system
CSF
cerebrospinal fluid
CT
computed tomography
CVA
cerebrovascular accident; stroke
EEG
electroencephalogram
EMG
electromyography
EST
electric shock therapy
ICP
intracranial pressure
LOC
level of consciousness
LP
lumbar puncture
MRI
magnetic resonance imaging
MS
multiple sclerosis
MSLT
multiple sleep latency test
NCS
nerve conduction study
NPH
normal-pressure hydrocehalus
NREM
non-rapid eye movement (stage of sleep)
PEG
pneumoencephalogram
PET
positron emission tomography
PNS
peripheral nervous system
PSG
polysomnogram
REM
rapid eye movement (stage of sleep)
RT
reading test
SNS
somatic nervous system
TENS
transcutaneous electrical nerve stimulation
TIA
transient ischemic attack
