brain blood vessels - blood supply to the CNS & intracerebral bleeds Flashcards
what 2 paired arteries are responsible for blood supply to the brain?
-vertebral artery
-internal carotid arteries
which artery is the vertebral artery a branch of?
the subclavian artery
what artery is the internal carotid artery a branch of?
- branch of common carotid artery
what do the terminal branches of these 2 paired arteries form in the brain?
terminal branches of these arteries form an anastomotic circle, called the Circle of Willis
at what vertebral level does the common carotid artery bifurcate?
C4
through which ‘canal’ does the ICA ascend into the brain?
- carotid canal
once the ICA has entered the cranial cavity, what structure does it pass through?
passes through the cavernous sinus anteriorly
what are the branches of the ICA?
-ophthalamic artery
-anterior choroidal artery
-posterior communicating artery
-2 terminal branches : anterior and middle cerebral artery
what does the ophthalmic artery supply?
supplies structures of the orbit
what does the anterior choroidal artery supply?
supplies structures in the brain important for motor control and vision.
-also supplies optic chiasma, optic tract, lateral geniculate etc
what’s the function of the posterior communicating artery ?
acts as an anastomotic ‘connecting vessel’ in the Circle of Willis
where do the arteries lie within the 3 layers of the meninges?
the subarachnoid space
what are the branches of the vertebral artery?
-PICA - posterior inferior cerebellar artery
-anterior spinal arteries
-posterior spinal arteries
-meningeal branch
what does the meningeal branch of the vertebral artery supply?
falx cerebelli, a sheet of dura mater.
what do the anterior and posterior spinal arteries supply?
supplies the spinal cord, spanning its entire length.
what does the PICA artery supply?
the cerebellum
once the vertebral arteries branch out, what do they do?
the two vertebral arteries converge to form the basilar artery
through what foramen does the vertebral arteries ascend into the cranial cavity ?
foramen magnum
what does the basilar artery supply?
-posterior circulation of brain
-goes along the midline of the pons
what are the branches of the basilar artery? ALPS
-AICA - anterior inferior cerebellar arteries
-labryrinthine arteries
-pontine arteries
-superior cerebellar arteries
what is the circle of willis?
a circle - in which the internal carotid artery and vertebral arteries anastomose and communicate with each other
what are the 3 main paired arteries of the circle of willis?
-Anterior cerebral arteries – terminal branches of the internal carotid arteries.
-Internal carotid arteries – located immediately proximal to the origin of the middle cerebral arteries.
-Posterior cerebral arteries – terminal branches of the basilar artery
what are the 2 connecting vessels in the circle of willis?
-Anterior communicating artery – connects the two anterior cerebral arteries.
-Posterior communicating artery – branch of the internal carotid, this artery connects the ICA to the posterior cerebral artery.
what are the 3 cerebral arteries?
-anterior
-middle
-posterior
