Blood Supply of the Brain Flashcards
What are the two main arteries supplying the cerebral region?
Internal Carotid - supplies most of the cerebrum
Vertebrobasilar - supplies brainstem, cerebellum and spinal cord
What are the branches of the internal carotid artery supplying the brain?
Ophthalmic Artery
Anterior Choroidal Artery
Posterior Communicating Artery
It bifurcates into the Anterior and Middle Cerebral Artery
What forms the basilar artery?
The fusion of the vertebral arteries
What are the vertebral branches of the vertebrobasilar artery?
Posterior and Anterior Spinal Artery
Posterior Inferior Cerebellar Artery
What are the basilar branches of the vertebrobasilar artery?
Anterior Inferior Cerebellar Artery
Superior Cerebellar Artery
It bifurcates into the posterior cerebral arteries.
Where do most strokes occur?
Most strokes occur on the internal carotid, and specifically on the middle cerebral artery.
What is the Circle of Willis?
It connects the anterior and posterior circulations and also has intracranial-extracranial anastomoses (external- internal carotid artery, carotid-basilar, carotid-vertebral)
What supplies the deep cerebral structures?
Small Perforating Arteries
Branches of the MCA
Is the Circle of Willis always complete?
No. In fact, it is often incomplete in many people.
What problems does hypertension present?
It can damage small blood vessels, which would affect organs like the kidneys, eyes and brain
How is blood flow to the CNS controlled?
Autoregulation with smooth muscle and arterial cells.
Metabolic via a pathway where increased neuronal activity -> glutamate release -> activates astrocyte end feet receptors -> vasodilator factors are released
What are the main barriers of the CNS?
Blood-Brain Barrier
Blood-CSF Barrier
Arachnoid Barrier
What is the main composition of the blood-brain barrier?
Capillary endothelial cells
What is a key feature of cerebral veins?
The are valveless
What is the role of emissary veins?
They connect extra cranial veins with dural sinuses
