Systems Path I - Neuro PPT 1 Flashcards
what is the 3rd leading cause of death in the US
stroke
occlusion at ____ causes cortical infarcts with motor and sensory loss and often aphasia
trifurcation
occlusion at ____ reveals large infarct of the right hemisphere with swelling and focal dusky discoloration
middle cerebral artery
with age, astrocytes are prone to
develop glucose polymer inclusion bodies, termed corpora amylacea
_______ to the CNS as Schwann cells are the PNS
oligodendroglia cells
what is responsible for producing cerebrospinal fluid and consists of papillae with a highly vascular core covered by cuboidal epethelium
choroid plexus
what is rich in neurons, including cerebral cortex, cerebellar cortex, basal ganglia
gray matter
functions of the cerebral cortex
though, voluntary movement, language, reasoning, perception
functions of the cerbellum
movement, balance, posture
functions of the midbrain
vision, audition, eye movement, body movement
functions of the brain stem
breathing, heart rate, blood pressure
functions of the thalamus
sensory processing, movement
functions of hypothalamus
body temp, emotions, hunger, thirst, circadian rhythms
functions of the limbic system
emotions, memory
accumulation of CSF OR failure of CSF absorption from the cranial vault resulting in dilation of these structures
hydrocephalus
hydrocephalus: obstruction of foramen of Monro may lead to dilation of one or both lateral ventricles
non communicating or obstructive hydrocephalus
hydrocephalus: paired with degenerative disease, accompanied by normal intracranial pressure and is therefore also called a
normal-pressure hydrocephalus
60 yo patient, autopsy is showing lesion in ventricles (foramen of monro). diagnosis
non communicating type or obstructive type hydrocephalus
infancy and childhood, before the cranial sutures have fused, the head enlarges. leads to increased intracranial pressure with headache, confusion, etc
hydrocephalus in a newborn
brain may be forced out of one compartment into another
brain herniation
one hemisphere is forced under the falx, cingulate lobe is the first part of that hemisphere to be displaced
cingulate or subfalcine herniation
cingulate or subfalcine herniations may be associated with compression of branches of what artery
anterior cerebral artery
ipsilateral oculomotor nerve is crushed by the displaced temporal lobe, leading to ipsilateral pupillary dilation and paresis of all extra ocular muscles
uncinate or transtentorial herniation
medial displacement continues, the midbrain shifts away from the displaced hemisphere, leading to pressure affect on the contralateral cerebral pedicle
uncinate or transtentorial herniation
brainstem and cerebellum may be forced through the foramen magnum; compressed cerebellar tonsils and medulla may lead to lethal compression of vital meduallary centers
cerebellar tonsillar herniation
rounded lobules or the cerebellum to become herniated or to be moved or pressed away from their usual position inside of the skull downward through the large opening in the base of the skull (foramen magnum) into the spinal canal
chiari malformation
which form of chiari malformation is the simplest and most prevalent
chiari malformation 1 (CM1)
both hemispheres herniate transtentorially; causes dilation of the pupils, flaccidity and coma
central herniation
accumulation of the excess fluid within the brain parenchyma
cerebral edema
cerebral edema: water is driven across an intact blood brain barrier by osmotic forces; caused by failure of cells or systemic water overload
cytotoxic edema
cerebral edema: most common cause of edema, seen with neoplasms, abscesses, meningitis, hemorrhage, contusions, and lead poisoning
vasogenic edema
cerebral edema: interstitial edema involves overproduction so that the fluid seeps across the ependymal lining of the ventricles to accumulate within the white matter
interstitial edema
middle cerebral artery distribution is most commonly affected, obstruction of local blood supply by thrombosis or emoblism
focal cerebral ischemia
infracted tissue is infiltrated by macrophages, becomes grossly conspicuous and is called “laminar necrosis”
global cerebral ischemia (widespread neuronal death)
10 to 3 weeks, tissue liquefies, eventually leaving a fluid filled cavity lined by dark gray tissue which gradually expands
cerebral infarction
results from venous sinus thrombosis, grossly they are very hemorrhagic
venous infarction
52 yo patient demonstrating a cystic lesion involving the lateral left frontal lobe
left frontal infarct (cystic lesion)
ischemic changes in neurons are called
red neurons
how does an infarct become cystic
phagocytosis of the necrotic, lipid rich tissue by macrophages, which migrate into the infarct during the final week (takes about 6 months)
major risk factors for development of cerebral atherosclerosis
hypertension, smoking, hyperlipidemia, diabetes, and aging
50 yo male patient was found unconscious and vigorously resuscitated, generalized swelling and irregular discoloration of gray matter, features indicative of irreversible, widespread brain injury caused by total circulatory arrest
global hypoxic ischemic encephalopathy
hypertensive cerbro vascular accident: filled with scattered lipid laden macrophages and surrounding gliosis
lacunar infarcts
transient weakness and speech difficulty likely reflect brief episodes of vascular occlusion by small embolic fragments
transient ischemic attacks (occurs with patients with atherosclerotic stenosis)
extravasation of blood with compression of adjacent parenchyma; causes are hypertensive hemorrhages
intraparenchymal hemorrhage
hemorrhagic necrosis are mostly _____ in origin; seen in the _____ or _______
venous
superior sagittal sinus or deep cerebral veins
rupture of ‘berry aneurysms” is most frequent cause of the ______, may be due to extension of traumatic hematoma
subarachnoid hemorrhage
what is the most common predisposing factor to spontaneous brain parenchymal hemorrhage
hypertension
strokes due to ischemia/infarction
- large vessel atherosclerotic disease (non-hemorrhagic)
- embolic (hemorrhagic)
- hypertensive (hemorrhages and lacunars)
- vasospasm (second to subarachnoid hemorrhage)
- watershed infarct (hypertension or hypoxia)
- venous thrombosis
- TIA
strokes due to hemorrhage
- hypertension (most common)
2. aneurysms like berry aneurysm or subarachnoid hemorrhage
blow to the head with skull fracture
epidural hematoma
significant cause of death after head injuries from falls, assaults, vehicle accidents, and sport injuries
subdural hematoma
occurs in the boxing ring as the consequence of a blow that deflects the head upward and posteriorly or seen in football injuries
parenchymal injuries (concussion)
when the brain strikes the irregular bony contours of the skull as a result of abrupt acceleration or deceleration
cerebral contusion or brain bruise
penetrating traumatic brain injury: absence of direct damage to the vital brain centers, immediate threat to life is
hemorrhage
