Cerebral Vascular and CSF Systems Flashcards
does grey or white matter receive greater cerebral BF
if cerebral BF is less than 35ml per 100g per minute what occurs
what is normal cerebral BF
grey matter
ischemia
55ml per each 100g per minute
total intracranial blood volume turns over __-__ times per minute
why is cerebral BF locally regulated
5-7
to ensure a constant BF
T or F: the concentration of metabolites (O2 and CO2) influence BF
what does hypoxia (low O2) and hypercarbia (high CO2) result in
what does hypocarbia result in
T
cerebral vasodilation and increased BF
vasoconstriction and diminished BF
what can cause increased intracranial pressure
what is the treatment for increased intracranial pressure
bleeding in the brain, tumor, stroke, aneurysm, high BP, brain infection
hyperventilation to reduce BF and pressure temporarily
what is the blood brain barrier
what does the blood brain barrier prevent
the passage of substances across the barrier depends on what 3 things
the barrier between the vascular system and brain
substances entering the cerebral space via tight junctions in capillary endothelium
molecular size, lipid miscibility, degree of ionic dissociation
what does a leaky blood brain barrier result in
what causes a leaky barrier
disease (epilepsy, alzheimer’s, MS)
when the junctions become not as tight as they should be, letting in harmful substances
which artery supplies the anterior and posterior blood supply
what structures do the right and left common carotid arteries branch off of
anterior: carotid artery
posterior: vertebral artery
R: brachiocephalic trunk
L: highest part of aortic arch
what do the carotid body and carotid sinus branch into
the anterior blood supply system starts at which structure
the internal/external carotid
the aorta
the internal and external carotid arteries play a role in what 3 things
what arteries come off of the internal carotid artery
BP, respiration, carotid pulse
anterior communicating artery, anterior cerebral artery, middle cerebral artery, opthalamic artery, anterior choroidal artery, posterior communicating artery
what does the anterior communicating artery join
what does the anterior communicating artery supply
the anterior communicating artery is an important source of BF for what part of the brain
the two anterior cerebral arteries
part of the corpus collosum
between the two hemispheres (especially if one internal carotid is blocked)
the anterior communicating artery is a frequent site for what
T or F: aneurysms are asymptomatic until they rupture
aneurysm formation
T (results in a hemorrhagic stroke when they rupture)
what portions of the brain does the anterior cerebral artery supply
if there was a blockage in this artery would there be deficits in the lower or upper extremities and why
inferior and medial surface of frontal and parietal lobes
the lower extremities because this artery supplies the medial surface of the brain and that is where the somatotopy for the lower extremities are
what portions of the brain does the middle cerebral artery supply
a stroke to this artery would result in what impairments and in what part of the body
if the stroke is in the dominant hemisphere what impairment may you see
if the stroke is in the non dominant hemisphere what impairment may you see
lateral surface of the frontal, parietal and temporal lobes
severe sensorimotor deficits in the contralateral face and upper limb
global aphasia (effects receptive and expressive language, auditory and visual comprehension)
neglect syndrome (don’t recognize contralateral side of the body)
which artery is most often occluded
what arteries arise from the vertebral artery
middle cerebral artery
posterior inferior cerebellar artery, anterior spinal artery, basilar artery, anterior inferior cerebellar artery, pontine arteries, superior cerebellar artery, posterior cerebellar artery
what brain structure does the posterior inferior cerebellar artery supply
stroke in the distribution of what 2 arteries results in Wallenburg syndrome
cerebellum
vertebral artery or posterior inferior cerebellar artery
what are the symptoms of wallenburg syndrome
ipsilateral loss of pain and temperature sensation in the face
contralateral loss of pain and temperature sensation in the limbs, trunk and neck
ipsilateral Horner syndrome (drooping eyelid and constructed pupil)
hoarseness, vertigo, double vision
ipsilateral cerebellar ataxia (impaired coordination and balance)
ipsilateral loss of taste
what arteries and branches provide blood supply to the spinal cord
what 3 arteries supply blood to the brainstem
anterior spinal artery, posterior spinal arteries, radicular and segmental branches
anterior inferior cerebellar artery, pontine arteries, superior cerebellar artery
the superior cerebellar artery, pontine arteries and anterior inferior cerebellar artery supply what structure in the brainstem
the posterior cerebral artery supplies what portions of the brain
superior: dorsal surface of cerebellum and midbrain
pontine: pons
anterior: cerebellum and pons
medial/inferior surface of temporal and occipital lobe, small portion on lateral surface of occipital lobe
what artery does the posterior cerebral artery supply
stroke in the distribution of the posterior cerebral artery results in what impairment
what is impaired if damage occurs in the dominant hemisphere
the calcarine artery
homonymous hemianopsia (entire visual field on the opposite side of the stroke is affected)
reading and writing
what surface of the brain is the cerebral arterial circle (circle of Willis) located on
what arteries make up the circle of Willis
the circle of Willis allows for ___ circulation in the case that something becomes ___
ventral
anterior communicating, anterior cerebral, internal carotid, posterior communicating, posterior cerebral, basilar
collateral (circulation from L and R side), occluded
how do cerebral veins differ from systemic veins
there are ___ and ___ portions of the venous drainage system which both drain into large __ ___
draining veins empty into larger ___
they don’t have valves or muscle tissue to assist and regulate flow
superficial and deep, draining veins
sinuses
what is a cerebral venous sinus thrombosis and what does it result in
what is a cerebral venous sinus thrombosis caused by
what are risk factors for a cerebral venous sinus thrombosis
a blood clot that forms in the sinuses preventing blood from draining out resulting in hemorrhage
bacterial infections or malignancy
pregnancy and oral contraceptives (because they increase the risk for blood clots in general)
what are the 3 sinuses of venous drainage
all sinuses drain into the ___ sinus, then into which structure
where does the internal jugular vein carry blood
inferior sagittal sinus, superior sagittal sinus, transverse sinus
sigmoid, internal jugular vein
back to the barchiocephalic veins which merge to form the superior vena cava
where are sinuses located
what is the falx cerebri
what is the purpose of dural folds
between periosteal and meningeal layer of the dura mater
a dural fold that separates the right and left hemispheres of the brain
provide support to the brain and dural venous sinuses
what are the 3 dural folds in the brain and where are they located
falx cerebri: vertical between two cerebral hemispheres
tentorium cerebelli: horizontal between cerebral hemispheres and cerebellum
falx cerebelli: vertical between cerebellar hemispheres
where is the dura mater adhered to
what two layers is the dura mater between
the dura mater is separated from the arachnoid mater by which space
cranium
outer periosteal layer and inner meningeal layer
subdural space
T or F: the arachnoid mater covers the brain but does not follow all of its contours
the arachnoid mater is separated from the pia mater by which space
what does this space contain
T
the subarachnoid space
CSF, cerebral arteries and veins
the pia mater is adhered to what
T or F: the pia mater does not follow the contours of the brain
the surface of the brain, spinal cord and cranial nerves
F
which arteries are involved in a subarachnoid hemorrage
what is a subarachnoid hemorrhage caused by
which veins are involved in a subdural hemorrhage
which vessels are involved in an epidural hemorrage
cerebral arteries
aneurysm rupture
cerebral veins
meningeal vessels running on the inside surface of the cranium
where does bleeding occur in a subarachnoid, subdural and epidural hemorrhage
subarachnoid: subarachnoid space
subdural: between arachnoid mater and dura mater
epidural: between dura mater and skull
where is CSF located in the brain
what is the purpose of CSF
CSF is produced by what structure and where is it located
in the subarachnoid space and ventricles
acts as a cushion for the brain, removes metabolic waste, maintains stable ionic environment
choroid plexus in the lateral, third and fourth ventricles
how much CSF is produced a day
how many times a day is CSF replenished and why
a majority of the CSF is produced in which ventricles
500mL
3-4 times to remove waste
lateral ventricles
explain the flow of CSF through the brain
lateral ventricles, interventricular foramen, third ventricle, cerebral aqueduct, fourth ventricle, median/lateral aperture, subarachnoid space around brain and spinal cord, absorbed into dural veinous sinuses
what is hydrocephalus
what is hydrocephalus caused by
what is it result in
abnormal collection of CSF
obstruction of the CSF pathway causing stagnation of flow
dilation of parts of the ventricular system
what is obstructive hydrocephalus (caused by, where is accumulation of CSF)
what is communicating hydrocephalus (caused by, where is accumulation of CSF)
what is the treatment for hydrocephalus
a congenital malformation or tumour, within ventricles
hemorrhage or infection, outside ventricles (subarachnoid space)
a shunt inserted into the ventricle to allow for drainage towards the heart
