CNS Arterial Supply Flashcards
Basilar artery bifurcates into _____ at midbrain.
2 PCAs
Before it bifurcates the Basilar artery gives off ____ & ____
AICA & SCA
What does AICA supply?
Anterior portions of inferior cerebellum, like flocculus & caudal pons
What does SCA supply?
Supplies superior cerebellum, caudal midbrain, rostral pons
What does does the Vertebral-Basiliar system supply?
Brainstem & cerebellum
Vertebral arteries run along lateral medulla & fuse to basilar artery at _____
pons
Prior to fusing with the basilar artery each gives rise to …
Posterior spinal artery, anterior spinal artery, PICA
What does the posterior spinal artery supply?
posterior 1/3 of spinal cord
What do the anterior spinal arteries supply?
They join in the midline resulting in a single artery that supplies anterior 2/3 of spinal cord
The circle of willis connects ___ & ___, via _____
IC & Vertebral-Basiliar system, via Pcomm
What connects the right and left sides of the circle of willis?
Acomm
What is the path of Pcomm?
It passes posteriorly, inferior to the optic tract towards the cerebral peduncle and joins PCA, which is part of the vertebral system
What is the path of the internal carotid arteries?
Ascends neck, traverses petrous temporal bone, goes thru cavernous sinus, ophthalmic artery branches off as IC enters subarachnoid space, then IC travels along the optic chasm
IC bifurcates into ___ & ____
Middle & Anterior Cerebral Arteries
Prior to the bifurcation of the IC it gives off ____ & _____
anterior chorodial artery & Pcomm
___ ___ artery is long & thin, and clinically significant in strokes
anterior choroidal artery
What does the anterior choroidal artery supply?
optic tract, choroid plexis in temporal horn of lateral ventricle, internal capsule, thalamus, hippocampus, sometimes cerebral peduncle
_______ run laterally into lateral sulcus & divides into many branches
Middle cerebral artery
What is the path of the anterior cerebral artery?
It runs medially and enters the longitudinal fissure, then it arches posteriorly & follows corpus callosum
What does the anterior cerebral artery supply?
medial parts of frontal and parietal lobes
What connects the 2 anterior cerebral arteries?
the anterior communicating branch
What are lenticulostriate arteries?
Perforating arteries from MCA
Perforating arteries are numerous around what structures?
optic chiasm, between cerebral peduncles, anterior & posterior perforated substance
What do perforating arteries supply?
basal ganglia, thalamus, & internal capsule
Perforating arteries arise from ____ at the _____
all arteries, at the base of the brain
True or false: Perforating arteries can be involved in strokes & cause neurologic deficits out of proportion to their size.
True
Which two pairs of vessels supply much of the brain & spinal cord?
internal carotid arteries, vertebral arteries
Define blood-brain barrier
Anatomic & physiologic barrier that controls movement of materials from extracellular fluid of body to extracellular fluid of brain
The blood-brain barrier includes . . .
arachnoid, endothelial tight junctions & lack of pinocytic vesicles
____ soluble substances go thru the blood-brain barrier
Lipid
Glucose crosses the blood-brain barrier by _____
facilitated diffusion
Other substances cross the blood-brain barrier by ____
active transport
Define circumventricular organs
Areas where cerebral capillaries are fenestrated allowing open communication between blood & brain extracellular fluid
Where are circumventricular organs located?
around 3rd & 4th ventricles
What are the functions of circumventricular organs?
some have sensory functions that monitor CSF composition others release hormones from neuronal endings into the blood
What are tancytes?
specialized ependymal cells that overlie the ventricular surface of circumventricular organs
What does the Posterior Cerebral Artery supply?
medial & inferior surfaces of temporal & occipital lobes, rostral midbrain & posterior diencephalon
