lecture 5: blood supply Flashcards
what are the two primary sources of blood to the brain bilaterally
1) internal carotid arteries (anterior system, 80%)
2) vertebral arteries (posterior system, 20%)
in what foramen do the vertebral arteries pass
transverse foramina
the common carotid bracnhes off what
either the aorta or the brachiocephalic trunk
the common carotid splits into what
internal and external carotid aa
true or false: the external carotid arteries provide primary blood supply to the. brain
false, interior
the subclavian a branches off what
the aorta
what early branch of the subclavian a is considered a primary source of blood supply to the brain
vertebral a
what major artery make up the anterior brain blood supply
internal carotid
which main arteries make up the posterior brain blood supply
vertebral arterieis
what is the site of anastamoses in the brain called
cerebral arterial circle
what branches off the vertebral arteries are important in the posterior system
- Anterior (ventral) spinal arteries
- Posterior inferior cerebellar arteries (PICA)
- Posterior (dorsal) spinal arteries
vertebral arteries join to form what a at the midline
basilar artery (located on basilar part of the pons)
what are the important branches off the basilar arterior for circulation
anterior inferior cerebellar arteries
internal auditory arteries
poutine arteries
supereical cerebrellar arteries
what are the important arteries for blood supply to the cerebellum off of the vertebral and basilar artery
anterior inferior cerebellar a
posterior inferior cerebellar
superior cerebellar a
Basilar artery branches terminally into what two arterries
posterior cerebral arteries
what is the most rostral branch off the basillar artery that supplies the cerebellum
superior cerebellar a
what are the two main arteries that supply the spinal corf
posterior spinal arteries (2)
anterior spinal a (1)
true or false, the anterior spinal a branch off the basillar a
false, branch off the vertebral arteries
true or false: the posterior spinal a branch off the bascillar a
false, it branches off the vertebral artery (or PICA)
what are the two general ways the spinal cord gets blood supply
1) off radicular arteriore
2) off segmental medullary arteries
where do radicular a arrise from
segmental spinal arteries (usually comin off a major verssel like the post intercostal)
what do radicular a in the spinal cord supplu
supply spinal roots and rootlets
true or false: radicular a of the spinal cord are only at some spinal levels,
false they are al every spinal level
what are the vessels called that arise from segmental spinal aa and supply spinal roots and rootlets
radicular arteries
what is the function of the segmental medullary a
reinforce anteior and posterior spinal arteries
are segmental medullary aa at all or only some spinal levels
only at some spinal levbels
what is the largest segmental medullary artery and where is it located
great segmental medullary artery
=lower thoracic and upper lumbar region
why is there the largest segmental medullary a located in the lower thoracic and upper lumbar region
because that provides blood supply to lumbosacral plexus (enlargement) which then innervates the nervous system for the whole lower limb
most of the supply to the spinal cord is done by what vessel
anterior spinal a
explain the perfusion area of the anterior spinal a
supplies most of the spinal cord
(anterior and lateral horns as well as their columns)
would there be sensory only, motor only or both deficits if there was a blockage of the anterior spinal a and why
both sensory and motor since it is supplying most of the spinal cord (anterior and lateral horns)
would there be sensory only, motor only or both deficits if there was a blockage of the posterioe spinal a and why
sensory only (since posterior only supplies the dorsal horns and columns)
true or false: there is 1 main longitunial vein that drains blood from the spinal cord
false thre is two
what is are the 2 main drainage systems for blood in the spinal cord
anterior spinal vein
posterior spinal vein
where do the longitudinal veins of the spinal cord drain
into the internal vertebral plexus
where is the internal vertebral plexus located
in the adipose filled space (in epidural space) surrounding meningeal layers of the spinal cord
where does the internal vertebral plexus drai
into major systemic veins (ex: inf vena cavam azygous veins) via small segmentally aranged vesseks
internal carotid arteries continue as what (after giving some branches)
middle cerebral artery
explain the passage of the internal carotid a
through transverse foramina, up through carotid canal and makes an S shape through cavervous sinus
what are some branches off the internal carotid a (before it becomes middle cerebral)
opthalamic
anterior choroidal
anterior cerebral aa
lenticulostriate aa
after what 3 branches does the internal carotid a continue as middle cerebral
ophthalmic arteries
anterior choroidal aa
anterior cerebral aa
what is a deep branch off the internal cartoid
lenticulostriate artieies
true or false: the ophthalmic aa branch off the middle cerebral a
false, off the internal carotid
the anterior cerebral aa branch off what vessel
internal carotid aa
where do the anterior cerebral artieries go after branching off internal carotid
enter the median longitudinal fissure
what deep branches off the anterior cerebral arteries go to subcortical structures
medial striate arteries
the lenticulate arteries branch off what vessel
middle cerebral arties
anterior choroidal artery supplies mostly which ventricle
lateral
true or false, the anterior and posterior blood systems never meet in the brain
false, they do, cerebral arterior circle (circle of willis(
what is the reason that the anteior and posterior blood systems anastamose
compensate for slow, chronic, changes in blood flow
balance blood pressure between left and right halvs
what are the two communicating arteries of the cerebral arterial circle
anterior communicating
posterior communicating
how many anterior communicating aa do we have
1
how many posterior communicating aa do we have
2
the anterior communicating a connects what
the left and right anterior cerebral arteries
the posterior communicating a connects what
internal carotid a with posterior cerebral a
which of these vessels is not part of the cerebral arterial circle:
internal carotid
postreior communicating
meiddle cerebral
anterior cerebral
middle cerebral
true or false: the middle cerebral artery is part of the circle of willis
false it is not
what vssels make up the circle of willis
left and right internal carotod
left and right anterior cerebral
left and right posterior cerebral
left and right posterior communicating
anterior communicating
which structures sit in the middle of the circle of willis
optic chiasm (and optic nevbres)
pituitary gland
mamalary bodies
what are the 3 main arteries that provide cortical perfusion
anterior cereal
posterior cerebral
middle cerebral
explain cortical perfusion area of the anterior cerebral artery
medial aspect of frontal and parietal lobes
1-2 cm on lateral aspects of frontal lobe and parietal lobes
deep branches also supply the caudate nucleus
explain perfusion area of the middle cerebral a
vast majority of the lateral cortex
(frontal aspects of superior and middle frontal gyri)
frontal pole of temporal lobe
insula
lentiform nucleus (globus pallidus and putamen)
true of false: the middle cerebral artery also supplies the insula and why
true because it passes thru lateral fissure
explain perfusion of the posterior cerebral a
entire occipital lobe
medial and inferior aspects of the temporal lobe (coveres the inferior, parahippocampal and occipitotemporal gyri)
thalamus (deep branches)
true or false: the entire occipital lobe is supplied by posterior cerebral a
true
true or false: the entire temporal lobe is supplied by the posterior cerebral artery
false, only the medial and ingerior aspects (inf, parahippocampal and occipitotemporal)
what are watershed regions
border zones between perfusion areas that are prone to ischemic stroke during hypoperfusion
true or false: the borders between vessels are prone to ischemic stroke
true, they are watershed regions
loss of blood supply to the cerebellum is associated with what
impaired motor coordination, stabilitiy and or balance
what are the 3 vessels that provide cerebellar perfusions
superior cerebellar artery
anterior inferior cerebellar a
posterior inferior cerebllar a
be able to locate the cerebellar perfusion area
review tyhe brainstem perfusion patterns
what are aneurysms
bulging/outpouching due to weakness or abnormality in arterior wall
where do saccular brain aneurysms commonly occur
where brain vessels meet
what is the issue with having aneurysms near brainstem
can pressure against cranial nerves
what are some treatment options for aneurisms
clipping
microcolis
stents
what is a storke
temporary or permanent loss of blood supply to a region of the brain
what are the 2 types of stroke and quickly define
ischemic (blocked vessel ex: embolus)
hermmoragic (ruptured or compromised vessel)
true or false: ischemic strokes are due to ruptured or compromised vessels
false, hemmorgaic strokes are
which of the following is part of the cerebral arterial circle
middle cerebral artey
superior spinal a
anterior communicating a
pontine as
anterior communicating a
a patient is experiencing motor and somatosensory deficits in their left lower limb due to an ischemic stroke. which vessel supplying the right cerebral cortex is most likely affected
anterior cerebral atery
whichh vessel supply the superior aspect of the cerebellum
superior cerebellar a
which vessel supplies the lateral tips of the cerebellum from a posterior view
anterior inferior cerebellar a
which vessel supples the posterir inn aspect of the cerebellum
posterior inferior cerebellar a
which vessel supples the peduncles of the cerebellum
anterior inferior cerebellar a
where does the superior cerebellar a branch from
basilar
where does the posterior inferior cerebellar a branch from
vertebral
where does the anterior inferior cerebellar a branch from
basilar
what are the 2 vessels that supply the midbrain
posterior cerebral (majority)
superior cerebellar (dorsal)
what are the 3 vessels that supply the pons
bascillar (majority)
anterior inferior cerebellar a (lateral)
superior cerebellar (dorsal)
what are the 3 vessels that supply the rostral medulla
anterior spinal (medial)
vertebral (middle)
posterior inferior cerebellar a (lateral and inferior)
what are the 3 vessels that supply the. caudal medulla
anterior spinal (medial)
vertebral a (middle)
posterior spinal a
what is the only difference in blood supply to rostral medulla vs caudal medulla
rostral = PICA
caudal = posterior spinal
