The blood in the vessels normally does not clot because:
|A||Vitamin K antagonists are present in plasma|
|B||Thrombin has positive feedback on plasminogen|
|C||Sodium citrate in plasma chelates calcium ions.|
|D||Vascular endothelium is smooth and coated with glycocalyx|
I. Intact endothelial cells serves primarily to inhibit platelet adherence and blood clotting.
II. Injury or activation of endothelial cells, however, results in a procagulant phenotype that augments local clot formation. Role of vascular endothelium in hemostasis
III. The vascular endothelium acts as a barrier between the thrombogenic subendothelial tissue and the blood
IV. The smoothness of endothelial cells hinder platelet aggregation
V. They manufactures heparin and α2macroglobulin which are coagulation inhibitors.
VI. These cells manufactures' PGI2 (prostacyclin) which opposes platelet aggregation.
Factors opposing coagulation existing clots and platelets plugging and accruing naturally
A. Opposing coagulation Q
B. Causing lysis of existing clot Q
C. Opposing platelet aggregation
• Antithrombin III
• Proteins C
Endoperoxidase from platelets
- Vit K dependent factor II, VII, IX, X, CS Q
- Factor II (prothrombin), VII, IX, and X. Protein C and proteins S Q
- Factors synthesis by liver 2, 7, 9,10, CS + 1,5,11 Q
- Factor I (fibrinogen), II (Prothrombin), V, VII, IX, X, XI Q
- Protein C and proteins S Q
- Antithrombin III and heparin Q