4. Blood supply to brain

Question 1

what are the two sources of arterial blood to the brain?

Answer 1

anterior circulation - internal carotid arteries feeds it and supplies cerebral hemispheres and deep branches - lentiform nucleus, caudate, internal capsule
posterior circulation - vertebral arteries feeds it and supplies brainstem, cerebellum, some of temporal and occipital lobe

Question 2

what is the anterior circulation?

Answer 2

internal carotid - middle cerebral and anterior cerebral. the left and right anterior cerebral arteries anastomose in midline via anterior communicating artery. these vessels loop over corpus callosum and send branches to cortex and supply forntal and parietal lobes

Question 3

what is the posterior circulation?

Answer 3

vertebral arteries (give branch of posyeoror inferior cerebellar and spinal cord one) come together to form basilar artery and then gives rise to posterior cerebral artery which supplies occipital lobe, inferior temporal, thalamus. posterior communicating arteries branch and connect with anterior circulation. superior cerebellar artery supplies superior of cerebellum and pontine arteries to pons, anterior inferior cerebllar arteries supplu anteroinferior aspect of cerebellum and lateral pons

Question 4

how is the spinal cord supplied with blood?

Answer 4

vertebral arteries give rise to anterior spinal arteries which converge in midline to supply anterior 2/3 of spinal cord.