Haemostasis Part 1

Blood clotting or haemostasis is the mechanism by which bleeding from a damaged blood vessel is stopped.

Blood clots have two major components. The first component is a platelet component known as a platelet plug. The second component is a factor component called a fibrin mesh.

Content Guide:

In parts 1 and 2 we discuss the formation of the platelet plug. We discuss the mechanism of platelet activation and aggregation.

In parts 3 and 4 we then discuss the formation of the fibrin mesh from the clotting factors through the coagulation cascades. Both the intrinsic and extrinsic pathways are discussed.

In part 5 we discuss some examples of bleeding disorders in which there are problems with the clotting pathways discussed prior. The disorders discussed are haemophilia, liver failure and vitamin K deficiency.

In part 6 we discuss the pathogenic activation of the clotting pathway in thrombosis and discuss the endogenous antithrombotic mechanisms of the vascular endothelium which try to prevent this.

In part 7 we discuss fibrinolysis, which is the mechanism by which the body breaks down blood clots.

In the playlist on pharmacology there is a 2 part video entitled ‘Anticoagulants and Thrombolytics’. This video discusses the pharmacology of anticoagulants, antiplatelets and thrombolytics and was made to be watched after this video on the clotting pathway. It builds upon the knowledge presented here to explained the mechanism of action of many clinically used drugs.

[hhijazi]

Pretty damn good explanation if you ask me