PHY3171 Lecture Notes - Lecture 14: Tight Junction, Posterior Cerebral Artery, Internal Carotid Artery
10 Feb 2019
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Document Summary
Insufficiency of blood supply: glucose + oxygen depravation, build-up of wastes. Ischemia for just a few second can have little to no damage. But 6-8 minutes is cerebral infarction where neurons + other cells die. Glucose is primary fuel source for brain. Safety mechanisms allow for uninterrupted blood flow: however specific areas can be highly vulnerable to great network of capillaries, but safety mechanisms to cope with vulnerability. Local control (slide 13: local flow linked to regional brain activity hyperaemia, glucose, o2 delivery, co2 (h+) waste, tightly autoregulated. Brain is enclosed in a rigid container: skull allows brain matter to be protected. Weak extrinsic control (slide 14: systemic changes. Internal carotid arteries: each supply ~40% cbf, subclavian steals. Vertebral arteries: these both branch around the brain, not into it, allows a number of branches vasculature that maintains demands, don"t enter brain but branch to: basilar and branches of pons, medulla and. Basilar and branches cerebellum: pons, medulla and cerebellum.
