lecture 3 - blood supply Flashcards
is the internal carotid 1 or 2 arteries?
2
what is origin of the internal carotid artery?
aorta –> common carotid –> internal carotid
how does the internal carotid enter the cranium?
via the carotid canal
what are the main branches of the internal carotid artery?
posterior communicating, anterior cerebral, anterior communicating, middle cerebral and anterior choroidal arteries (4)
is the posterior communicating 1 or 2 arteries?
2
what does the posterior communicating artery supply?
parts of the thalamus and hypothalamus
is the anterior communicating 1 or 2 arteries?
1
what does the anterior communicating artery supply?
parts of the hypothalamus
is the anterior cerebral 1 or 2 arteries?
2
what does the anterior cerebral artery supply?
medial inferior frontal lobe, and medial parietal lobe
is the middle cerebral 1 or 2 arteries?
2
what does the middle cerebral artery supply?
insula, precentral and postcentral gyri, lateral inferior frontal lobe, lateral parietal lobe, lateral temporal lobe, lateral occipital lobe
is the anterior choroidal 1 or 2 arteries?
1
what does the anterior choroidal artery supply?
optic tract, parts of the internal capsule, diencephalon
is the vertebral 1 or 2 arteries?
2
what is the origin of the vertebral artery?
aorta –> subclavian artery –> vertebral artery
how does the vertebral artery enter the cranium?
via the foramen magnum (through transverse processes of the neck)
what are the main brances of the vertebral artery?
- PICA
- anterior spinal arteries
- posterior spinal arteries
is the PICA 1 or 2 arteries?
2
what does the PICA supply?
inferior anterior cerebellum, medulla
is the anterior spinal 1 or 2 arteries?
1
what does the anterior spinal artery supply?
anterior 2/3 of the spinal cord, medulla
is the posterior spinal 1 or 2 arteries?
2
what does the posterior spinal artery supply?
posterior 1/3 of the spinal cord, medulla
what do the vertebral arteries supply?
medulla
what do the vertebral arteries merge to form?
the basilar artery
is the basilar 1 or 2 arteries?
1
what does the basilar artery supply?
medulla, pons and midbrain
what are the branches of the basilar artery
AICA, pontine branches, superior cerebellar arteries, posterior cerebral arteries
is the AICA 1 or 2 arteries?
2
what does the AICA supply?
inferior anterior cerebellum, pons
is the pontine branches 1 or 2 arteries?
multiple little arteries (usually 3-5)
what do the pontine branches supply?
pons
is the superior cerebellar 1 or 2 arteries?
2
what does the superior cerebellar artery supply?
cerebellum, midbrain, medulla
is the posterior cerebral 1 or 2 arteries?
2
what does the posterior cerebral artery supply?
medial inferior occipital lobe, medial inferior temporal lobe and the midbrain (1^0)
what forms the circle of willis?
the anterior communicating, anterior cerebral, internal carotid, posterior communicating, and posterior cerebral arteries
what sits inside the circle of willis?
- optic chiasm
- pituitary gland
what is the functional significance of the cirlce of willis?
to maintain blood supply to the brain, should one of these major arteries be damaged
what are the superficial veins?
superior cerebral veins, superficial middle cerebral vein
how many superior cerebral veins are there?
8-12
what is the function of the superior cerebral veins?
to drain the lateral surface of the cerebral hemispheres
where do the superior cerebral veins empty into?
superior saggittal sinus – – – – > internal jugular veins
how many superficial middle cerebral veins are there?
1
what is the function of the superficial middle cerebral vein?
to drain the lateral surface of the cerebral hemispheres
where does the superficial middle cerebral vein empty into?
cavernous sinus
where do the superficial veins lie?
in the subarachnoid space
how many internal cerebral veins are there?
2
what is the function of the internal cerebral veins?
to drain the deep parts of the cerebral hemispheres
where do the internal cerebral veins empty into?
empty into transverse, straight and sigmoid sinuses
where does the great cerebral vein (of Galen) empty?
straight sinus
what are dural sinuses?
valveless, venous channels in the located between the two dural layers
whare are the major dural sinuses? (8)
- superior sagittal sinus
- inferior sagittal sinus
- straight sinus
- occipital sinuses
- transverse sinuses
- sigmoid sinuses
- cavernous sinuses
- superior ( 1) and inferior (2) petrosal sinuses
where is the superior sagittal sinus?
runs along the superior edge of the falx cerebri
where does the superior sagittal sinus drain?
into the condfluence of sinuses
where is the inferior sagittal sinus?
runs along the inferior edge of the falx cerebri
where does the inferior sagittal sinus drain?
into the straight sinus
where is the straight sinus?
at the junction between the falx cerebri and the tentorium cerebelli
where does the straight sinus drain?
into the confluence of sinuses
where are the transverse sinuses?
run through the tenorium cereblli
where do the transverse sinuses drain?
into the sigmoid sinus
where are the sigmoid sinuses?
near the middle inner ear, covered by the temporal bone
where do the sigmoid sinuses drain?
into the internal jugular vein
so what is the confluence of sinuses?
connecting point of superior saggittal sinus, straight sinus, and the occipital sinus
where is the confluence of sinuses?
at the occipital pole of the skull
where does the confluence of sinuses drain?
into the transverse sinuses
where are the cavernous sinuses?
on either side of the pituitary fossa and body of sphenoid bone
where do the cavernous sinuses drain?
superior and inferior petrosal sinuses
where does the superior petrosal sinus drain?
into the transverse sinuses
where do the interior petrosal sinuses drain?
into the internal jugular veins
where is the superior petrosal sinus?
between petrous part of temporal bone and tentorium cerebelli
where is the inferior petrosal sinus?
inferior border of petrous part of temporal bone
what is the blood brain barrier?
a highly selective, semipermeable border of endothelial cells
what is the function of the blood brain barrier?
to regulate the entry of nutrients, exit of waste, and ion/fluid movement
what are the structural components of the BBB?
- endothelial cells
- basement membrane
- astrocytes
describe endothelial cells as a component of the BBB
- have TIGHT junctions (what makes them different)
- secrete inactivating enzymes
describe the basement membrane as a component of the BBB
has pericytes and macrophages
describe pericytes
vascular cells embeded in the basement membrane of the BBB - function to maintain it
describe astrocytes as a component of the BBB
- essential for forming the BBB - ensure tight junctions
- also important for maintenance
