6 - Arterial Supply to the Brain Flashcards
Label the following arteries that make up the cerebral circulation.
What vessels make up the Circle of Willis?
2 posterior communicating arteries and 2 anterior communicating arteries, both to the ICA
What is the anterior cerebral circulation made up of and what regions of the brain does it supply?
- Two main branches from the ICA: MCA and ACA
Middle Cerebral Artery:
- Lateral frontal and parietal loves (involved in lateral sensory and motor homunculus)
- Superior temporal lobe (visual pathway runs through)
Anterior Cerebral Artery:
- Medial frontal and parietal lobes (involved in medial sensory and motor homunculus)
What are the deep branches of the middle cerebral artery and what do they supply?
- Lenticulstriate arteries that supply major motor pathways
- Really tiny so can quickly become blocked
- Most affected artery in strokes
What is the posterior cerebral circulation made up of and what regions of the brain does it supply?
- From the vertebral arteries
- Both give off a branch as they go through F.Magnum that joins to form anterior spinal artery that supplies anterior 2/3 of the spinal cord
- Vertebrals merge to form basilar artery. All supplies posterior brain
- Basilar then becomes two posterior cerebral arteries
What is the course of the vertebral arteries from the heart to the brain?
Subclavian –> Vertebral –> Foramen Magnum –> Basilar Artery
Apart from the MCA and ACA, what are some other branches of the internal carotid artery that contribute to the cerebral circulation?
- Opthalmic artery
- Anterior choroidal artery
What are the branches of the basilar artery and what do the branches supply? (midline artery)
- Pontine Arteries: supply pons of brainstem
- Superior cerebellar arteries: supply top of cerebellum and midbrain
- Anterior inferior cerebellar arteries: supply anterior inferior cerebellum and pons
- Posterior inferior cerebellar artery supplying cerebellum and medulla
- 2 posterior cerebral arteries: supply occipital and inferior temporal lobes, midbrain and thalamus and go on to form posterior communicating artery
Therefore if patient has cerebellum damage check for brainstem damage!
What happens if there are damage to the pontine arteries?
Locked in syndrome where you can only move your eyes but you still have your consciousness
How can you tell the difference between an anterior and posterior circulation stroke?
Anterior usually unilateral but posterior bilateral and affecting consciousness (google)
What is the course of the anterior cerebral artery?
Goes towards the midline and arches over the corpus callosum and the anterior communicating artery anastomoses the two
How can you find the posterior cerebral artery in the cadaver?
Follows the shape of the midbrain, runs backwards
What is the difference between the anterior and posterior cerebral circulation?
Anterior: from ICA and supplies most of the cerebral hemispheres
Posterior: from vertebral arteries and supplies brainstem, cerebellum, some of temporal and occipital lobe
What are the branches of the middle cerebral arteries?
- Directly from ICA
- Cortical branches emerge from the lateral fissure to supply the lateral cerebral hemisphere (cortex and underlying white matter), including lateral parts of the frontal and parietal lobes as well as the superior temporal lobe
- Deep branches (the lenticulostriate arteries) supply deep grey matter structures including the lentiform nucleus and caudate as well as the internal capsule
What would be the difference in motor signs between a stoke in the ACA and MCA?
ACA: issue with lower limbs
MCA: issue with face and upper limbs
Which cerebellar arteries supply each part of the brain stem?
All supply cerebellum plus
Superior: midbrain
Anterior inferior: pons
Posterior inferior: medulla
What are the thalamopeforator and thalamogeniculate arteries?
Thalamogeniculate: branch of PCA supplying medial and lateral geniculate nucleus and the pulvinar nuclei of the thalamus
Thalamoperforator: supply the medial surfaces of the thalami and the walls of the third ventricle
