4.2 arterial supply to the brain Flashcards
what are the two main sources of arterial blood to the brain?
anterior circulation
- internal carotid arteries
they supply most of the cerebral hemispheres
posterior circulation
- vertebral arteries
supplies brainstem, cerebellum, some of the temporal lobe and the occipital lobe
how does the middle cerebral artery relate to the anterior circulation?
internal carotid arteries continue to become middle cerebral artery
1) cortical branches emerge from the lateral fissure to supply the lateral aspect of the cerebral hemispheres (cortex and underlying white matter).
2) deep branches supply deep grey matter structures including lentiform nucleus and caudate as well as the internal capsule
how does the anterior cerebral artery relate to the anterior circulation?
a branch of the internal carotid artery
L and R anterior cerebral arteries anastomose in midline to form anterior communicating artery
vessels loop over corpus callous and send branches to the adjacent cortex
cortical branches supply the medial aspect of the frontal and parietal lobes
there are NO branches to the corpus calloum itself
how does the basilar artery relate to the posterior circulation?
a midline vessel formed from the confluence of vertebral arteries
terminal bifurcation gives rise to posterior cerebral artery which supplies occipital lobe, interior temporal lobe and the thalamus, as well as the midbrain
supeior cerebral artery branches off it and supplies superior aspects of cerebellum and midbrain
pontine arteries supply the pons and descending corticospinal fibres
anterior inferior cerebellar artery supplies the antero-inferior aspect if the cerebellum and the lateral pons
also get vertebral branches from it = get anterior spinal arteries, which converge in midline and supply anterior 2/3rds of spinal cord
posterior inferior cerebral artery supplies the poster-inferior aspects of the cerebellum en passant
