Cerebrovascular Anatomy
M. Christopher Wallace M.D.
The Toronto Western Hospital,
University Health Network
University of Toronto
Postgraduate Lecture Series
Division of Neurosurgery
Friday October 6, 2000
Collateral Circulation
• Circle of Willis• Variation• Leptomeningeal
Collateral
Cerebral Autoregulation
• Maintenance of blood flow during variation in blood pressure
• Change in blood flow related to metabolic activity
Mechanism for Cerebral Autoregulation?
• Myogenic
• Neurogenic
• Metabolic
Measurement of Cerebral Blood Flow
• Seymour Kety• Delivery of blood flow to given wt of brain per
time period– 50ml/100grams/minute
Brain takes 12-15% of cardiac output
Internal Carotid Artery
• Divisions: cervical, petrous, cavernous, infraclinoid, supraclinoid
• Branches: meningohypophyseal trunk• dorsal meningeal artery, tentorial artery, inferior
hypophyseal
• artery of the inferior cavernous sinus
• capsular arteries of McConnell
Internal Carotid Artery
Internal Carotid Artery
• Supraclinoid
• Branches – Ophthalmic– Posterior communicating– Anterior choroidal
Bifurcation
Middle Cerebral Artery
• Variation
• Divisions (M1-M4)
• Lenticulostriate arteries
– medial
– lateral• putamen, caudate, sup
internal capsule
Anterior Cerebral Artery
• Variation• Divisions (A1-A4) • Anterior communicating artery
• Lamina terminalis, septal region, fornix, preoptic/hypothalamus
Recurrent artery of Heubner
Anterior putamen, pallidum and internal capsule