Blood Supply Flashcards
why is blood supply so important
- CVD and CVA - constitute the most common cause of neurological deficits
- TIAs (total ischemic attacks) - sudden drop of systemic BP
- Hemorrhagic vs. Thrombolytic strokes
- Aneurysms
Internal Carotid Artery
anterior circulation –> 80% blood supply to cortex
Branches internal carotid artery
Anterior cerebral artery
Middle cerebral artery
Posterior communicating artery
Watershed zones
Anterior Cerebral Artery
Runs in longitudinal fissure
Supplies medial aspect of the frontal and parietal lobes and medial sensorimotor cortex
Anterior communicating artery (btw the two anterior cerebral arteries)
Middle Cerebral Artery
Supplies virtually entire lateral surface of cerebral hemispheres
Specialized Branches –> Lateral Striate going to basal nuclei and internal capsule (stroke central)
Superior and Inferior divisions
Middle Cerebral A. Superior Division
Cortex above lateral fissure
Supplies lateral frontal cortex including precentral and postcentral gyri
Middle Cerebral A. Inferior Division
cortex below lateral fissure
supplies lateral temporal lobe, parts of the parietal lobe
Posterior communicating artery
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Watershed Zones
Regions of the cortex between two cerebral vessels
Infarcts in the areas can occur with severe drops in systemic blood pressure
Interphases btw two major blood supplies
Vertebral - Basilar System
Posterior circulation, 20% blood supply to cortex
Branches from vertebral
Posterior spinal arteries
Anterior spinal artery
Posterior inferior cerebellar artery
Branches from Basilar
Anterior inferior cerebellar artery
Superior cerebellar artery
Pontine arteries
Posterior cerebral artery
Posterior Spinal Arteries
Off vertebral
Run caudaully on dorsolateral sulci of spinal cord
Reinforced b arteries (parietal brs) as the descend
Anterior Spinal Artery
Off vertebral
Joins its mate from opp side forming one single artery
Runs in anterior median fissure - along the ventral midline of the spinal cord
Paramedian branches supply medial caudal medulla
Reinforced by arteries (parietal brs.) as it descends
Posterior Inferior Cerebellar Arteries
Off vertebral
Supplies inferior surface of the cerebellum, choroid plexus, lateral medulla
Anterior Inferior Cerebellar Arteries
off basilar
Supplies the anterior, inferior surface of the cerebellum and caudal lateral pons
Superior Cerebellar Arteries
off basilar
Supply superior surface of the cerebellum, caudal midbrain (tectum) and rostral pons
Pontine Arteries
off basilar
paramedian branches supply medial pons
circumferential branches supply lateral pons
Terminal of Vertebral-Basilar System
Superior Cerebellar Arteries
Posterior Cerebral Arteries
Posterior Cerebral Arteries
Arise from bifurcation of basilar at level of midbrain
Supplied midbrain, most of thalamus, medial and inferior surfaces of the occipital and temporal lobes including hippocampus
Branches from posterior cerebral arteries
Parietooccipital branch and Calcarine branch (visual cortex)
Also thalamoperfortor, thalamogeniculate, and posterior choroidal arteries
Posterior Cerebral anastomasoses with
ant cerebral
Circle of Willis
the communication of anterior and posterior circulations to the cerebrum and brainstem
(not a true anastomotic circle)
Circle of Willis - Wada test
Cannulate the internal carotid artery and infuse barbituates to put the cortex to sleep. Patient will read passage until unconscious. depending on speech before unconscious state will determine dominant hemisphere - primarily done with left handed people
