300816 Lecture Notes - Lecture 6: Vasospasm, Hemostasis, Blood Vessel
Document Summary
~ ischaemia = an inadequate blood supply to an organ or blood supply. ~ infarction = the obstruction of the blood supply to an organ or region of tissue. A sudden and severe loss of blood can lead to shock and death. When blood vessels are damaged, haemostasis (clot formation) will arrest bleeding. Cutting or damaging blood vessels leads to a vascular spasm of the smooth muscle in the vessel wall. This produces a vasoconstriction which will slow or even stop blood flow. In larger blood vessels, platelets begin to stick to the surfaces of endothelial cells; platelet adhesion. The platelets that adhere to the walls secrete adenosine diphosphate (adp). This material causes the aggregation of nearby free platelets which attach to the fixed platelets and each other eventually leading to the formation of a platelet plug. This clumping of platelets serves a number of functions: It can plug the break in a small blood vessel.
