blood supply and stroke: CSF Flashcards
cerebrovascular disease:
- affects 500,000 per year
- 3rd leading cause of death
- leading cause fo neurologic disability
- include strokes
what are the 2 kinds of strokes?
- ischemic
- hemmorhagic
ischemic strokes
- blood clot prevents blood flow to brain
- if it stay deprives for a few mins, the Na/K pump will not work
- damage to cell and cell death
hemmorhagic stroke
- blood vessel in brain breaks open
- blood flow into skull
- cause edema
- often occurs due to aneurysms (weakened arterial walls)
what is the occurance of ischemic vs hemorrhagic strokes?
ischemic = 80%
hemmorhagic = 20%
what arteries supply the brain?
- internal carotids
- vertebral arteries
the circle of willis
arteries included
BLOOD DOES NOT FLOW THROUGH THE CIRCLE OF WILLIS, IT IS SOMETHING FORMED BY THE CONNECTIONS
- vertebral arteries
- basilar artery
- posterior cerebral arteries
- superior cerebellar artery
- anterior inferior cerebellar artery
- posterior inferior cerebellar artery
- internal carotids
- middle cerebral
- anteriror cerebral
- posterior communicating
- anterior communicating
where deos the vertebral artery enter the skull and join to form the basilar artery?
basus pontus
superior cerebellar artery supplies:
the superior surface of the cerebellum
the anterior inferior and posterior inferior cerebellar arteries supply:
the brain stem
which artery branches to for the middle and anterior cerebellar arteries?
internal carotid
what is the path of the middle cerebral artery?
- sylvian fissure between hemispheres
- supplies medial surface of the cortex
the anterior cerebral artery pathway
- travels the longitudinal fissure between hemispheres
- curves over corpus callosum
- supplies medial surface of the cortex
- connected by anterior communicating artery
what connects the posterior cerebral and internal carotid arteries in the circle of willis?
posterior communicating artery
what hooks behind the oculomotor nerve?
posterior cerebral artery
where is the circle of willis located?
base of the brain
vertebral arteries
- left and right
- form the basilar artery
the internal carotid arteries
- paired
- branch into the middle cerebral, anterior cerebral, and posterior communicating arteries
- mainly flow into the middle cerebral
the middle cerebral artery
descriptions
- largest branch of the internal carotid
- enters sylvian fissure
- supplies later surface of hemisphere (except occipital lobe)
- supplies basal ganglia and internal arteries
striate arteries
- branches go to the internal capsule to the white matter and to the basal ganglia
- are branches of the middle cerebral artery
arteries from lateral view of sagittal cut
posterior cerebral artery
- comes from basilar artery
- supplies occipital lobe and inferior surface of temporal lobe
- curve around midbrain
- linked to internal carotid by posterior communicating artery
- behind occlulomotor nerve
color coded labeling of arteries
cortical territories suppied by the cerebral arteries
in order to solve clinical problesm we have to know somatotopic organzaiton of the motor and somatosensory cortex!!
on exam?
Question 1: what signs and symptoms are noted following the occlusion of the anterior cerebral artery?
- motor weakness of contralateral leg
- somatosensory loss of contralateral leg
- mental confusion
question 2: what signs and symptoms are noted following occlusion of the middle cerebral artery?
- spastic paralysis contralateral
- speech and comprehension deficits
- weakness of mastication, swallowing, and speech (internal capsule)
question 3: what signs and symptoms are noted following occlusion of the posterior cerebral artery?
contralateral vision blindness
the meninges include:
- dura mater (hard shell covering, outermost)
- arachnoid mater (thin)
- pia mater (covers surface of brain and SC)
the layers of the dura mater:
- endosteal: closer to skull
- meningeal: covers the ondosteal layer
the dural folds include:
- falx cerebri - separates hemispheres
- tentorium cerebelli - divides cortex from occipital lobes
- falx cerebelli
- diaphragma sella
dural sinuses
- the area where veins empty
- spaces created by the dural folds
what do veins ultimately drain into?
internal jugular vein
arachnoid mater
- bridges over sulci
- subarachnoid space contains CSF
CSF is:
formed? provides?
- in ventricles of the brain then go to subarachnoid space via the foramen of luschka and magendie
- mechanical hydraulic protection of the brain
CSF pathway
- lateral ventricles
- foramen of monro
- 3rd ventricle
- aqueduct of sylvius
- 4th ventricle
- foramen of luschka and magendie
- subarachnoid space
CSF
- synthesized by choroid plexus
- ultrafiltrate of plasma
- normally contains no RBC or leukocytes
CSF synthesis
- at a rate of 500 mL/day
- volume is 150mL of subarachnoid space
- constant flow
arachnoid granulation
- look like cauliflower protrusions in subarachnoid space
- absorb CSF and open onto the venous system
defintion of hydrocepahalus
- dilation of one or more of the cerebral ventricles with an incease in CSF volume
types of hydrocephalus
- communicating
- non-communicating
what causes hydrocephalus?
- occurs if there is a blockage of the CSF flow
- can be caused by tumor of choroid plexus
- overproduction of CSF (papilloma)
- defective absorption of CSF
obstruction of CSF pathways can be caused by:
- inflammation or hemmorhage
- congenital
- neoplasm (new abnormal growth)
overproduction of CSF due to:
- papilloma
defective absorption of CSF due to:
- defective arachnoid villi (cannot reabsorb)
- impaired venous drainage
