Coagulation Cascade - Brar Flashcards
What are the 4 major players in forming a clot?
- Endothelial Cells
- Subendothelial Cells
- Platelets
- Clotting factors
Endothelial cells have what affect on blood clotting?
Inhits it
Endothelial cells inhibit blood clotting by forming what, which inhibits platelet adhesion & aggregation?
Prostacyclin
Platelets release what after they bind to subendothelial tissue?
- Protiens
2. Vasoactive amines
Plasma protiens which create a proteolytic cascade which ends with the production of insoluble firbrin from soluble fibrinogen are called what?
Clotting factors
What mediates platelet adhesion to exposed extracellular matrix when the endothelial lining of blood vessel is damaged?
von Willebrand Factor (vWF)
vWF is a protein that is present where?
- Plasma
2. Extra cellular matrix
vWF binds to what?
- A receptor on the platelet membrane
2. Collagen fibers in the tissue
Adhered platelets by agents that increase the calcium concentration of platelets, which is typically what 2 agents?
- Thrombin
2. Thromboxane
During activation, a receptor for what becomes exposed on the platelet membrane?
Fibrinogen
Fibrinogen binds to a receptor exposed on the platelet membrane and causes what?
Platelet aggregation
Fibrinogen consists of how many pairs of polypeptides?
3
Fibrinogen is the precursor for what?
Fibrin
What converts fibrinogen into fibrin?
Protease thrombin
Why is fibrinogen more soluble than fibrin?
The fibropeptides are covered in negatively charged aspartate & glutamate residues (repel eachother)
The negative charges on fibrinopeptides help prevent what?
Aggregation
The crosslinking of fibrin is catalyzed by what?
Transglutaminase (factor XIII)
Thrombin formation is limited to where?
The site of injury
Thrombin is produced from prothrombin vi what?
Factor X a
The formation of Thrombin produces what other product?
A catalytically inactive fragment
The catalytically inactive fragment produced with thrombin has 10 residues of what?
Gamma- carboxyglutamate
Gamma- carboxyglutamates are produced by hepatocytes in a reaction requiring what?
Vitamin K