9. inhitor of coagulation blood hemostasis.pptx

Inhibitors of coagulation process

1. Inhibitors of coagulation Us/ Amani Awad Ashmaig

2. Inhibitors of coagulation They are naturally occurring factors act as anticoagulant by limitation the activation of coagulation factors to localize the clot. Function: Localization of haemstatic clot to the site of injury.

3. Physiological anticoagulants present in small concentration in the plasma in order to control the clotting mechanism. They insure that the production of fibrin clot limited to the site of injury and is not allowed to propagate. They are synthesized in the liver

4. Types of inhibitors of coagulation : 1/Blood flow 2/Serine proteases 3/Serine protease inhibitor

5. 1/Blood flow: Wash away the activated coagulation factor and platelet agonist to the liver to inactivated and removed by macrophage.

6. 2/Serine proteases : They are enzymes that cut certain peptide bonds in other proteins. Activated clotting factors act as serine proteases,such as: a. Thrombin (factor IIa ):degrade factor Xa b. activate protein C which with help of protein S inhibit factor Va and VIIIa

7. 3/Serine protease inhibitor : They are proteins able to  inhibit   proteases (activated clotting factors), include: a . Antithrombin III : inhibit factor IIa , IXa , Xa , XIa and XIIa . b. Heparin cofactor II : inhibit factor IIa (thrombin) c. Protein C with protein S as cofactor : inhibit factor Va and VIIIa d. Tissue factor pathway inhibitor Rapidly remove (tissue factor – FVIIa complex)  

8. Coagulation inhibitors: ATIII TFPI APC XIIa XIa IXa Xa IIa TF-VIIa VIIIa Va PS Xa