Nervous System Flashcards
what does the CNS consist of
brain and spinal cord
number of cranial nerves in the peripheral nervous system
12 pairs
number of spinal nerves in the peripheral nervous system
31 pairs
which nervous system supplies striated skeletal muscles
somatic nervous system
nervous system that supply smooth muscle, cardiac muscle, and glandular epithelial tissue
autonomic nervous system
nerves that conduct impulses from peripheral receptors to the central nervous system
afferent nerves
nerves that conduct impulses from the central nervous system to the peripheral receptors
efferent nerves
basic unit of a nerve that consists of body and threadlike extensions
neuron
part of a neuron that leads away from cell body
axon
fatty covering of axon that helps transmissions
myelin sheath
when is deterioration of the myelin sheath seen causing interruptions of signals to the muscles and other parts of the body
multiple sclerosis
section of a neuron that leads toward cell body
dendrite
where do impulses pass from one neuron to another
synaptic junction (chemical reaction)
2 hemispheres of the cerebrum are separated by a thin membrane called
corpus callosum
elevations on the surface of the brain
gyri
grooves on the surface of the brain
sulci
deep grooves that divide the cerebrum into 2 halves
fissures
outer portion of the cerebrum
cortex
inner portion of the cerebrum
white matter
few islands of gray matter that control position and automatic movement in the cerebrum
basal ganglia
largest part of the brain that is divided into two hemispheres
cerebrum
part of the brain responsible for receiving sensory information from all parts of the body through specialized areas
cerebral cortex
which part of the cerebral cortex receives information that is visual
posterior
which part of the cerebral cortex receives information that is olfactory (smell) and auditory
lateral
which part of the cerebral cortex receives information that is motor related
anterior
section of the brain that triggers impulses that govern all motor activity
cerebral cortex
controls movement of muscles and speech (left side in a right handed person)
premotor cortex
maintains memory and creative thought
cerebral cortex
made of pons and medulla, located between the cerebrum and the spinal cord
midbrain (mesocephalon)
contains nuclei of 12 cranial nerves and is a vital center for cardiac, vasomotor, and respiratory control
midbrain (mesocephalon)
controls vomiting, coughing, sneezing, hiccupping, and swallowing
medulla centers of midbrain
controls muscle movement, equilibrium, gait
cerebellum
lies between the cerebrum and midbrain, contains the thalamus and hypothalamus
dicenephalon
relay station that recieves and processes sensory information
thalamus
links mind and body, site of pleasure and reward, drives eating drinking and mating, coordinates ANS and secreting hormones from pituitary gland, maintains body temperature
hypothalamus
consists of inner core of gray matter and surrounded by white matter, conducts impulses from the brain to the rest of the body
spinal cord
bones that protect brain and spinal cord
skull and vertebra
covering of brain and spinal cord
meninges
innermost layer covering of brain and spinal cord
pia mater meninges
tough outer layer covering of brain and spinal cord
dura mater meninges
delicate layer covering between pia and dura mater
arachnoid membrain
where does CSF travel
through 4 ventricles in brain to spinal cord
an acute inflammation of the pia mater and arachnoid
memingitis
how organisms enter to cause memingitis
enter through the middle ear, upper respiratory tract, or frontal sinuses
some types of bacterial meningitis
haemophilus influenzae in neonates, meningiococci, pneumococci in adults
some types of viral meningitis
mumps, poliovirus, herpes simplex
may show arterial or venous vasculitis or thrombosis with infarction, hydrocephalus, thickening of arachnoid, subdural effusion, empyema or brain abcess
meningitis in CT or MRI
characterized by diffuse brain swelling may symmetrically compress the lateral and third ventricles
meningitis
viral inflammation of the brain and meninges characterized by mild headaches, fever, cerebral dysfunction, seizures, coma
encephalitis
microorganisms such as bacteria or fungi lodge into gray matter and spread to white matter, causing
brain abscesses
most common cause of brain abscesses
streptococci
on CT or MRI, an abnormal density with poorly defined borders and a mass effect reflecting vascular congestion and edema
brain abscess
make up 25% of intracranial infections, spread of infection from frontal and ethmoid sinuses, mastoiditis, middle ear infection, purulent meningitis, skull fractures, osteomyelitis of skull
subdural empyema
shown on MRI as compression and displacement of the ipsalateral ventricular structures
subdural empyema
infection between the cranial table and dura mater, stemming from osteomyelitis of the skull originating from ear or sinus infection
epidural empyema
shown on CT as poorly defined area of low density adjacent to the inner table of the skull
epidural empyema
pathology appears as multiple, small poorly defined lucencies that over time enlarge, caused by infections of the sinuses or scalp
osteomyelitis of the skull
what percentage of CNS tumors are primary lesions
50%
manifest as seizure disorders or gradual neurological deficits like difficulty speaking, slow comprehension, weakness, headache
tumors of the CNS
most common primary malignant tumor of the brain
glioma
benign tumor attached to dura mater arising from arachnoid lining cells, often found in the convexity of the calvaria, olfactory groove, tubercullum sellae, sylvian fissure or spinal canal
meningioma
slow growing bening tumor arising from Schwann cells in the 8th cranial nerve (auditory), usually originates in the internal auditory canal
acoustic neuroma
hypersecretion of ACTH causing gigantism in children
Cushings syndrome
10% of all intracranial tumors that arise in the anterior lobe, cause gigantism
pituitary adenoma
benign tumor containing cystic and solid matter originating from the sella turcica from embryonic remnants extending up into the 3rd ventricle
craniopharyngioma
rapidly growing germ cell tumors predominantly in males under 25, most common type of germinomas and teratomas
pineal tumor
tumor arising from notochord (embryonic neural tube) where the most common site is the clivus and lower lumbosacral region
chordoma
most commonly lung and breat carcinomas that reach the brain through hematogenous spread
metastatic carcinoma
caused by acute arterial bleeding (medial meningeal artery) and often over the patietotemporal convexity, rapidly causes neurologic deficits
epidural hematoma
venous bleeding caused by a rupture between the dura and meninges, neurological symptoms will appear in minutes
subdural hematoma
injury to the brain tissue by movement of the brain within the calvaria, most common in frontal region, patient loses consciousness and cannot remember traumatic event
cerebral contusion
can result from trauma to intraparenchymal arteries, appears in CT as well circumscribed homogeneous areas surrounded by edema
intracranial hematoma
occurs from injury to surface veins, cerebral parenchyma, or cortical arteries bleeding into the ventricular system
subarachnoid hematoma
result from trauma to the neck such as gunshots or stabbings, associated with 50% of traumatic fistulas
carotid artery injury
any process caused by an abnormality of the blood vessels or blood supply to the brain
vascular disease of CNS
meaning of hemiplagia
paralysis of one side
sudden and dramatic development in neurologic deficit, mild deficits to hemiplagia or coma
stroke syndrome
focal neurological deficits result from emboli from arteriosclerotic, ulcerated plaque causing occlusion of cerebral arteries
transient ischemic attack
people with TIAs have a 50% increase risk for
strokes
results from hyeprtensive vascular disease or rupture of an aneurysm or arterialvenous malformation, hypertensive hemorrhage, causes oval or circular collections displacing surrounding brain tissue
intraparenchymal hemorrage (hemorrhagic stroke)
rupture of berry aneurysm, cause excruciating headaches followed by unconsciousness
subarachnoid hemorrhage
most common demyelinating disorder, impairment of nerve conduction caused by degeneration of the myelin sheaths
multiple sclerosis
brain impulses are temporarily disturbed resulting in a loss of consciousness for a few seconds to violent tremors, shaking and thrashing movements that can result in physical injuries
epilepsy / convulsive disorders
generalized convulsions, foams at mouth, loss of control of urine and feces
grand mal
pre-senile dementia, diffuse form of progressive cerebral atrophy, causes loss of memory, disorientation, confusion
Alzheimer’s disease
inherited autosomal dominant condition, causes dementia with involuntary movements that are rapid, jerky, and continuous
Huntington’s disease
progressive degenerative disease caused by an enzyme deficiency resulting in decreased dopamine production, characterized by stooping posture, stiffness, slowness of movement, fixed facial expressions, involuntary rhythmic tremors
Parkinson’s disease
isolated atrophy of the brain resulting from degenerative disease, prolonged drug use, and long term use of antiseizure medication Dilantin
cerebellar atrophy
relentlessly progressive condition of unknown cause, widespread atrophy and loss of motor cells leading to extensive paralysis, respiratory weakness, aspiration pneumonia and death
Lou Gehrig’s Disease (amyotrophic lateral sclerosis)
dilation of the ventricular system associated with intracranial pressure, attributable to papillomas, colloid cyst, suprasellar tumor, craniopharyngioma, or blockage of duct of Sylvius
hydrocephalus
viral infection of upper respiratory tract that may lead to obstruction of drainage of the paranasal sinuses
sinusitis
