Internal carotid to each hemisphere. Only the arterioles can regulate blood flow. Peak incidence for cerebral thrombosis 50-70 years. Peak incidence for cerebral hemorrhage 40-70 years. C. Incidence Cerebrovascular disease - most common disorder in adults.
Basic process is that of atherosclerosis.
Involves large and medium sized arteries. Ischemia develops after 30 sec. of restriction. After 1 minute neural function may cease. After 5 minutes cerebral infarction develops. General preciptors fall in arterial pressure falls below reg.