12. Nervous System Flashcards
gli/o
glue
neur/o
nerve
astr/o
star
dendr/o
tree
neural functions
- Sensing: collecting data from the environment
- Interpreting: processing this data and choosing a response
- Acting: directing the body to act out that response
central nervous system (CNS)
composed of the brain and spinal cord, operated largely by a network of nerve cells called interneurons
peripheral nervous system (PNS)
extends from the brain and spinal cord to the tissues of the body
organized first into 12 pairs of cranial nerves and 31 pairs of spinal nerves
divided into afferent (sensory) or efferent (motor) nerves
also divided into somatic (controlling voluntary functions) and autonomic (controlling mostly involuntary functions)
afferent nerves
sensory nerves that carry impulses to the CNS
efferent nerves
motor nerves that carry impulses from the brain and spinal cord
interneurons
link the sensory and motor nerves by transmitting signals between them
Alzheimer’s disease (AD)
a progressive degenerative disease of the brain characterized by personality changes, confusion, restlessness, early senility, and a loss of memory that begins as a slight disturbance and progresses to profound dementia
disrupts the neurons’ roles in communication within the system, as well as their roles in metabolism and self-repair
brain in attached photograph shows smaller brain, narrow gyri, and widened sulci in comparison with a normal brain
neurons
any of the basic conducting cells of the nervous system
neuroglia
nur OGG lee uh
supporting or stromal (connective) tissue cells of the CNS
provide a supportive function by holding neurons together and protecting them
astrocyte
a type of neuroglia that forms the blood-brain barrier (BBB)
blood-brain barrier (BBB)
a network of connected neurons and blood vessels that prevents or slows the passage of harmful substances into the CNS
dendrite
one of the threadlike extensions of the cell body of a neuron to receive neural impulses - or action potentials - from a stimulus of some kind, and then delivers that impulse back to the cell body
axon
the extension of a neuron by which impulses travel away from the bell body
capable of conducting action potentials
neurotransmitter
any of a group of substances that travel across the synaptic cleft to inhibit or stimulate a target cell
released on excitation from the axon terminal of a neuron of the CNS or PNS
synapse
the space between the terminal fibers and the dendrites of the next cell
myelin sheath
a cylindrical structure composed largely of phospholipids and protein that covers the axons of some nerves in the body
hypothalamus
controls the PNS and functions such as temperature, sleep, and appetite
the ventral portion of the diencephalon, forming the floor and part of the lateral wall of the third ventricle
cerebrum
the main portion of the brain, occupying the upper section of the cranial cavity
its two hemispheres are connected by the corpus callosum and form the largest part of the CNS
cerebellum
portion of the metencephalon that is located in the posterior cranial fossa, behind the brainstem
coordinates voluntary movements
diencephalon
portion of the brain between the mesencephalon and the cerebrum
consists of the thalamus, hypothalamus, and epithalamus and including most of the third ventricle
brain stem
stalklike part of the brain comprising the medulla oblongata, pons, and mesencephalon
connects the cerebral hemispheres with the spinal cord
thalamus
responsible for relaying all sensory information (except smell) and translating it into sensation of pain, temperature, and touch
part of the diencephalon
midbrain
reflex center for eye and head movements
located in the brain stem, connecting the pons and cerebellum
AKA mesencephalon
pons
located between the mesencephalon and the medulla oblongata, superior to the cerebellum
medulla oblongata
regulates heart rate, blood pressure, and breathing
inferiormost part of brain stem
encephal/o
brain
cerebell/o
cerebellum
cerebr/o
cerebrum
dur/o
dura mater
gangli/o
ganglion
mening/o, meningi/o
meninges
radicul/o, rhiz/o
nerve root
cord/o, myel/o
spinal cord
spin/o
spine
spondyl/o, vertebr/o
vertebra
cerebral cortex
a layer of gray matter and neurons located on the surface of the cerebral hemispheres that serves to integrate general movement, higher mental functions, perception, visceral functions, and behavioral reactions
covers both hemispheres of cerebrum
gyri
JYE rye
the winding convolutions of the surface of the brain
ridges separated from each other by sulci (grooves)
frontal lobe
controls speech and voluntary movement on the contralateral side of the body
temporal lobe
contains auditory and olfactory areas
parietal lobe
controls touch and taste
occipital lobe
responsible for vision
spinal cord
extends from the medulla oblongata to the first lumbar vertebra, where it continues into a structure called the cauda equina
meninges
the 3 gray matter membranes enveloping the spinal cord and brain;
- pia mater
- dura mater
- arachnoid
dementia
chronic, progressive, organic mental disorder characterized by chronic personality disintegration
symptoms include confusion, disorientation, stupor, deterioration of intellectual capacity and function, along with impairment of memory/judgement/impulse control
dura mater
outermost, toughest, and most fibrous of the 3 membranes surrounding the brain and spinal cord
subdural space
located beneath the dura mater and above the arachnoid
arachnoid membrane
membrane between the dura mater and pia mater
pia mater
innermost of 3 membranes that cover the brain and spinal cord
consists of elastic, reticular, and collagenous fibers
carries a rich supply of blood vessels, which nourish the nervous tissues
contains cerebrospinal fluid (CSF)
cerebrospinal fluid (CSF)
fluid that flows through and protects the four ventricles of the brain, the spinal canal, and the subarachnoid spaces
consists primarily of secretions of the choroid plexi in the lateral ventricles and in the 3rd and 4th ventricles of the brain
plexus
a network of intersecting nerves and blood vessels or of lymphatic vessels
ganglion
a collection of nerve cell bodies in the PNS
dermatome
very specific skin surface area supplied by a single afferent spinal nerve
can be mapped with each dermatome named for the spinal nerve that serves it
cranial nerves
somatic nervous system
PNS component that controls voluntary activities
autonomic nervous system
PNS component that controls involuntary functions such as heartbeat, stomach contractions
sympathetic nervous system
a division of the autonomic nervous system (PNS) that helps the individual respond to perceived stress
responsible for the “fight-or-flight” response, in which heart rate and blood pressure increase, digestion slows, and sweat and adrenal glands increase secretion output
parasympathetic nervous system
a division of the autonomic nervous system (PNS) that sends signals that help to protect, conserve, and restore the body’s resources
responsible for the “rest and digest” response after a person has reacted to an emergency by slowing the heart rate, lowering blood pressure, increasing secretion of digestive juices, and relaxing muscles of the digestive system that control elimination
asthenia
as THEE nee ah
muscle weakness
amnesia
loss of memory caused by brain damage or severe emotional trauma
aphasia
lack or impairment of the ability to form or understand speech
dysphasia
dis FAY zsa
impairment of speech usually caused by an injury to the speech center area of the brain
consists of lack of coordination and inability to arrange words in proper order
AKA dysarthria
athetosis
ath uh TOH sis
continuous, involuntary, slow, writhing movement of the extremities
aura
sensation that may precede an epileptic seizure or the onset of some types of headache
may be a sensation of light or warmth
dysphagia
dis FAY jee uh
condition of difficulty with swallowing
fasciculation
involuntary contraction of small, local muscles
gait, abnormal
disorder in the manner of walking
ataxia
uh TACK see uh
a lack of muscular coordination, as in cerebral palsy
hypokinesia
decrease in normal movement that may or may not be due to paralysis
spasm
involuntary muscle contraction of sudden onset
ex: hiccups, tics, and stuttering
tremors
rhythmic, quicvering, purposeless skeletal muscle movements
paresthesia
feeling of prickling, burning, or numbness
parasomnia
disorder of sleep
hypersomnia
excessive depth or length of sleep
insomnia
inability to sleep or stay asleep
somnambulism
sleepwalking
seizure
neuromuscular reaction to abnormal electrical activity within the brain
causes include fever or epilepsy
AKA convulsions
tonic clonic (grand mal)
type of seizure accompanied by temporary loss of consciousness and severe muscle spasms
absence seizures (petit mal)
type of seizure accompanied by loss of consciousness exhibited by unresponsiveness for short periods without muscle involvement
status epilepticus
condition of intense, unrelenting, life-threatening seizures
syncope
fainting
vasovagal attack
a form of syncope that results from abrupt emotional stress involving the vagus nerve’s effect on blood vessels
tremor
rhythmic, quivering, purposeless skeletal muscle movement seen in some elderly individuals and in patients with various neurodegenerative disorders
vertigo
dizziness, sensation of spinning
Romberg sign
an indication of loss of the sense of position, in which the patient loses balance when standing erect, feet together, and eyes closed
acalculia
ay kal KYOO lee ah
inability to perform mathematical calculations
ageusia
ag GOO zsa
absence of the ability to taste
parageusia
pair ah GOO zsa
abnormal sense of taste or a bade taste in the mouth
agnosia
ag NOH zsa
inability to recognize objects visually, auditorially, or with other senses
agraphia
inability to write
anosmia
an NAHZ mee ah
lack of sense of smell
apraxia
ah PRACK see ah
inability to perform purposeful movements or to use objects appropriately
dyslexia
inability or difficulty with reading and/or writing
spina bifida
SPY nah BIFF uh dah
congenital condition in which the spinal column has an abnormal opening that allows the protrusion of the meninges and/or the spinal cord (meningocele)
meningocele
meh NIN goh seel
saclike hernial protrusion of the meninges through a bony defect in the skull or vertebral column
meningomyelocele
a herniation of the meninges and spinal cord through an opening in the spinal column
cerebral palsy (CP)
motor function disorder as a result of permanent, nonprogressive brain defect or lesion caused perinatally
neural deficits may include paralysis, ataxia, athetosis, seizures, and/or impairment of sensory functions
Huntington chorea
inherited disorder that manifests itself in adulthood as a progressive loss of neural control, uncontrollable jerking movements, and dementia
hydrocephalus
condition of abnormal accumulation of fluid in the ventricles of the brain
may or may not result in mental retardation
Tay-Sachs
inherited disease that occurs mainly in people of Eastern European Jewish origin
characterized by an enzyme deficiency that results in CNS deterioration
hematoma
HEM uh toh ma
localized collection of blood, usually clotted, in an organ, tissue, or space due to a break in the wall of a blood vessel
this bleeding causes pressure on the area of the brain where the hematoma has formed
coma
deep, prolonged state of unconsciousness from which the patient cannot be aroused
usually the result of a head injury, neurologic disease, acute hydrocephalus, intoxication, or metabolic abnormalities
concussion
serious head injury characterized by one or more of the following: loss of consciousness, amnesia, seizures, or a change in mental status
contusion, cerebral
head injury of sufficient force to bruise the brain
bruising of the brain often involves the brain surface and causes extravasation of blood without rupture of the pia-arachnoid
often associated with a concussion
extravasation
a discharge or escape of blood, lymph, or other fluid, normally found in a tube or vessel, into the surrounding tissues
amyotrophic lateral sclerosis (ALS)
ay mye oh TROH fick
degenerative, fatal disease of the motor neurons, in which patients exhibit progressive asthenia and muscle atrophy
AKA Lou Gehrig disease
Guillain-Barré syndrome
gee YAN bar AY
autoimmune disorder of acute polyneuritis producing profound myasthenia that may lead to paralysis
multiple sclerosis (MS)
neurodegenerative disease characterized by destruction of the myelin sheaths on the CNS neurons (demyelination or demyelinization) and their abnormal replacement by the gradual accumulation of hardened plaques
may be progressive or characterized by remissions and relapses
idiopathic
Parkinson disease (PD)
progressive neurodegenerative disease characterized by tremors; fasciculations; slow, shuffling gait; hypokinesia; dysphasia; and dysphagia
Bell’s palsy
paralysis of the facial nerve
etiology unknown
condition usually (but not always) resolves on its own within 6 mos
epilepsy
group of disorders characterized by some or all of the following: recurrent seizures, sensory disturbances, abnormal behavior, and/or loss of consciousness
narcolepsy
disorder characterized by sudden attacks of sleep
Tourette syndrome
abnormal condition characterized by facial grimaces, tics, involuntary arm and shoulder movements, and involuntary vocalizations, including coprolalia (the use of vulgar, obscene, or sacrilegious language)
encephalitis
inflammation of the brain, most frequently cased by a virus transmitted by the bite of an infected mosquito
meningitis
any infection of inflammation of the membranes covering the brain and spinal cord, most commonly due to bacterial infection, although more severe strains are viral or fungal in nature
neuritis
inflammation of the nerves
polyneuritis
inflammation of many nerves
radiculitis
inflammation of the root of a spinal nerve
sciatica
inflammation of the sciatic nerve
symptoms include pain and tenderness along the path of the nerve through the thigh and leg
shingles
acute infection caused by the latent varicella (herpes zoster) virus, characterized by the development of vesicular skin eruption underlying the route of cranial or spinal nerves
AKA herpes zoster
cerebrovascular accident (CVA)
ischemia of cerebral tissue due to an occlusion from a thrombus or embolus, or as a result of a cerebral hemorrhage
results of a stroke depend on the duration and location of the ischemia. These sequelae may include paralysis, weakness, speech defects, sensory changes that last more than 24 hours, or death
AKA stroke, brain attack, cerebral infarction, apoplexy (app poh PLECK see)
migraine
headache of vascular origin
may be classified as migrane with aura or migraine without aura
transient ischemic attack (TIA)
has the same mechanisms as a CVA, but the sequelae resolve and disappear within 24 hours
AKA mini-stroke
diplegia
dye PLEE jee ah
paralysis of the same body part on both sides of the body
hemiparesis
hem mee pah REE sis
muscular weakness of slight paralysis on the left or right side of the body
hemiplegia
hem mee PLEE jee ah
paralysis on the left or right side of the body
monoparesis
mah noh pah REE sis
weakness or slight paralysis of one limb on the left or right side of the body
monoplegia
paralysis of one lim on the left or right side of the body
paralysis
loss of muscle function, sensation, or both
may be described according to which side if affected and whether it is the dominant or nondominant side
paraparesis
slight paralysis of the lower limbs and trunk
paraplegia
pair uh PLEE jyuh
paralysis of the lower limbs and trunk
quadriparesis
weakness or slight paralysis of the arms, legs, and trunk
quadriplegia
kwah drih PLEE jya
parlaysis of arms, legs, and trunk
meningioma
slow growing, usually benign tumor of the meninges
although benign, may cause problems bc of size and location
neurofibroma
benign fibrous tumors composed of nervous tissue
neuroma
benign tumor of the nerves
astrocytoma
malignant tumor arising from star-shaped glial cells
most common in the cerebrum in adults
in children, these arise from the brainstem, cerebrum, or cerebellum
AKA glioblastoma multiforme
medulloablastoma
malignant tumor arising from embryonic tissue in the cerebellum
most commonly seen in children
neuroblastoma
highly maligant tumor arising from either tha autonomic nervous system or the adrenal medulla
usually affects children under the age of 10
para-
abnormal
gnos/o
knowledge
-lepsy
seizure
ischem/o
to hold back
-plegia
paralysis
esthesi/o
feeling
-fida
split
-sthenia
strength
geus/o
taste
prax/o
purposeful movement
-cephalus
head
phas/o
speech
-paresis
slight paralysis
encephal/o
brain
brain scan
nuclear medicine procedure involving intravenous injection of radioisotopes to localize and identify intracranial masses, lesions, tumors, or infarcts
photography is done by a scintillator or scanner
cerebral angiography
radiographs of the cerebral arteries, including the internal carotids, taken after the injection of a contrast medium
AKA cerebral arteriography
computed tomography (CT) scan
transverse sections of the CNS are imaged, sometimes after the injection of a contrast medium (unless there is suspected bleeding)
used to diagnose strokes, edema, tumors, and hemorrhage resulting from trauma
echoencephalography
ultrasound exam of the brain, usually done only on newborns, bc sound waves do not readily penetrate bone
magnetic resonance angiography (MRA)
imaging of the carotid arteries using injected contrast agents
myelography
radiographs of the spinal canal after the introduction of a radiopaque substance
positron emission tomography (PET)
use of radionuclides and sophisticated computerized scanner to demonstrate brain functions
measurements can be taken of blood flow, volume, and oxygen and glucose uptake, enabling radiologists to determine the functional characteristics of specific parts of the brain
used to assist in the diagnosis of Alzheimer disease and stroke
single-photon emission computed tomography (SPECT)
an injection of a radioactive sugar substance that is metabolized by the brain, which is then scanned for abnormalities
electroencephalography (EEG)
record of the electricla activity of the brain
may be used in the diagnosis of epilepsy, infection, and coma
evoked potential (EP)
electrical response from the brainstem or cerebral cortex that is produced in response to specific stimuli
results in a distrinctive pattern on an EEG
multiple sleep latency test (MSLT)
consists of a series of short, daytime naps in the sleep lab to measure daytime sleepiness and how fast the patient falls asleep
used to diagnose or rule out narcolepsy
nerve conduction test
test of the functioning of peripheral nerves
conduction time (impulse travel) through a nerve is measured after a stimulus is applied
used to diagnose polyneuropathies
polysomnography (PSG)
measurement and record of a number of functions while the patient is asleep (cardiac, muscular, brain, ocular, and respiratory functions)
most often use dto diagnose sleep apnea
Babinski reflex
in normal conditions, the dorsiflexion of the great toe when the plantar surface of the sole is stimulated
Babinski sign
the loss or dimunition of the Achilles tendon reflex seen in sciatica
cerebrospinal fluid (CSF) analysis
examination of fluid from the CNS to detect pathogens and abnormalities
useful in diagnosing hemorrhages, tumors, and various diseases
deep tendon reflexes (DTR)
assessment of an automatic motor response by striking a tendon
useful in the diagnosis of stroke
gait assessment rating scale (GARS)
inventory of 16 aspects of gait to determine abnormalities
may be used as one method to evaluate cerebellar function
lumbar puncture (LP)
procedure to aspirate CSF from the lumbar subarachnoid space
a needle is inserted b/w 2 lumbar verebrae to withdraw the fluid for diagnostic purposes
AKA spinal tap
craniectomy
removal of part of the skull
craniotomy
incision into the skull as a surgical approach or to relieve intracranial pressure
AKA trephination
CSF shunt
tube implanted in the brain to relieve the pressure of cerebrospinal fluid as a result of hydrocephalus
Fig A
stereotaxic radiosurgery
surgery using radiowaves to localize structures within 3-D space
Fig B
ganglionectomy
removal of a ganglion
vagotomy
vay GAH tuh mee
cutting of a branch of the vagus nerve to reduce the secretion of gastric acid
carotid endarterectomy
removal of the atheromatous plaque lining the carotid artery to increase the blood flow and leave a smooth surface
done to prevent thrombotic occlusions
microsurgery
surgery in which magnification is used to repair delicate tissues
nerve block
use of anesthesia to prevent sensory nerve impulses from reaching the CNS
neurectomy
excision of part or all of a nerve
neurolysis
destruction of a nerve
neuroplasty
surgical repair of a nerve
neurorrhaphy
noo ROAR ah fee
suture of a severed nerve
neurotomy
inciscion of a nerve
cordotomy
incision of the spinal cord to relieve pain
rhizotomy
RYE zah tuh mee
resection of the dorsal root of a spinal nerve to relieve pain
sympathectomy
sim puh THECK tuh mee
surgical interruption of part of the sympathetic pathways for the relief of chronic pain or to promote vasodilation
transcutaneous electrical nerve stimulation (TENS)
method of pain control affected by the application of electrical impulses to the skin
crani/o
cranium, skull
stere/o
3-D
tax/o
order, arrangement
