PSL301H1 Lecture Notes - Lecture 6: Platelet-Rich Plasma, Platelet-Activating Factor, Thromboxane A2
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PSL301H1 Full Course Notes
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Document Summary
Half life of platelets is 10 days. Platelets are smaller than rbcs, colorless with no nucleus: mitochondria, smooth er and granules that have cytokines and growth factors. Always present in blood and last about 10 days. Stop blood loss, but they also act as an immune cell mediator of in ammatory response. Platelet rich plasma therapy (prp) is popular for helping tendons and ligaments heal - evidence is not there yet. Hemostasis: process of keeping blood within damaged blood vessel. 3 main parts: vasoconstriction/vascular phase, temporary blockage of a break by a platelet plug, coagulation. 1. immediately constrict the damaged vessels to decrease blood ow and pressure within the vessel temporarily: done by the paracrine molecules released by endothelium - this decreases ow. Mechanical blockage of hole by loose platelet plug. Vasoconstriction prolonged by serotonin, endothelia 1 and thromboxane a2. 1. starts with platelet adhesion, when platelets stick to exposed collagen in damaged area.
