1. CEREBRAL VASCULAR SUPPLY

2. General Information Brain receives 20% of the cardiac output. Brain receives 20% of the cardiac output. Major arterial supply via: Major arterial supply via: Internal carotids: Give off paired anterior cerebral arteries. Give off paired middle cerebral arteries. Vertebral arteries: Join to form unpaired basilar artery

3. Posterior Inferior Cerebellar Aa Branches of vertebral arteries. Branches of vertebral arteries. To: To: Dorsolateral part of medulla Posterior choroid plexus Posterior/inferior parts of cerebellum Form unpaired anterior spinal artery. Form unpaired anterior spinal artery. Form basilar artery. Form basilar artery.

4. Basilar Artery Branches Anterior inferior cerebellar artery Anterior inferior cerebellar artery To upper medulla and pons Internal auditory artery Internal auditory artery To part of inner ear Pontine arteries Pontine arteries To pons Superior cerebellar artery Superior cerebellar artery Terminate as posterior cerebral arteries Terminate as posterior cerebral arteries

5. Posterior Cerebral Arteries Terminal branches of basilar artery. Terminal branches of basilar artery. To: To: Medial and inferior surfaces of the temporal and occipital lobes, posterior thalamus.

6. Posterior Cerebral Arteries Occlusion results in thalamic syndrome: Occlusion results in thalamic syndrome: Contralateral diminishing of general somatic modalities in head (ventral posterior nucleus). Contralateral diminishing of general somatic modalities in head (ventral posterior nucleus). Threshold for pain, temperature, and tactile sensation on contralateral side of head raised. Threshold for pain, temperature, and tactile sensation on contralateral side of head raised. Mild stimuli may produce disagreeable sensations. Mild stimuli may produce disagreeable sensations.

7. Middle Cerebral Branches Largest branches of internal carotid arteries. Largest branches of internal carotid arteries. Run between temporal and frontal lobes. Run between temporal and frontal lobes. To most of lateral surfaces of cerebrum. To most of lateral surfaces of cerebrum. Give off striate arteries: Give off striate arteries: To internal capsule and adjacent structures. Stroke: Contralateral upper motor-neuron paralysis of face and UE/LE as well as sensory disturbances.

8. Anterior Cerebral Arteries Branches of internal carotid arteries. Branches of internal carotid arteries. Give off perforating arteries to hypothalamus. Give off perforating arteries to hypothalamus. Extend rostrally and then curve upwards and backwards around corpus callosum: Extend rostrally and then curve upwards and backwards around corpus callosum: Pericallosal arteries Occlusion: Occlusion: Contralateral paresis and diminished sensitivity in LE.

9. Circle of Willis Interconnects vertebral and internal carotid supply. Interconnects vertebral and internal carotid supply. Components: Components: Posterior cerebral arteries Posterior communicating arteries Internal carotids Anterior cerebral arteries Anterior communicating artery

10. Watershed Areas Border zones of cerebral arteries. Border zones of cerebral arteries. Decreased blood supply. Decreased blood supply. Hypoperfusion may result in: Hypoperfusion may result in: Paralysis/sensory loss bilateral UE Disturbed vision Disturbed memory ChoreaAphasia