The document discusses the factors that prevent intravascular coagulation. There are three main factors: 1) Endothelial surface factors like the smoothness and glycocalyx layer of endothelial cells, which provide a barrier between blood and tissues. 2) The speed of blood flow, as higher speeds prevent clot formation. 3) The presence of natural anticoagulants like heparin and antithrombin-III, which inactivate thrombin and other clotting factors. The endothelial cells also secrete substances like prostacyclin and nitric oxide that prevent clotting.

1. WHAT ARE THE FACTORS THAT
PREVENT INTRAVASCULAR
COAGULATION? DISCUSS.
Hare Ram Karn
2009928111

2. Coagulation
Due to :
- Trauma to the blood
- Trauma to the tissue
- Contact of Blood with collagen fibers
- Damaged Endothelial cells
Soluble Fibrinogen Insoluble Fibrin
Formation Of ClotFormation Of Clot

3. FACTORS :
1 Endothelial Surface Factors
2 Speed of the blood Flow
3 Presence of Natural Anticoagulants
- Heparin
- Antithrombin-III

4. ANTICOAGULATING ROLE OF ENDOTHELIAL
CELLS
- Provide intact barrier between
blood and subendothelial
connective tissue.
- Synthesize and release PG & NO
- Secrete TPA
- Display Heparin Molecule on its own
Plasma membrane
-Bind Thrombin via thrombomodulin
receptor

5. ENDOTHELIAL SURFACE
FACTORS
 Smoothness of The Endothelium
 Presence of Monomolecular Protein
 Presence of Glycocalyx

6. THROMBOMODULIN
ANTICOAGULANT
MECHANISM
-

7. HEPARIN
-Usually present in low concentration.
-Has no or little anticoagulant properties.
-Becomes effective after combining with
Antithrombin III for the inactivation of
Thrombin,thus acts as anticoagulants.
-Heparin-Antithrombin III complex also
inactivates other activated factor IX, X, XI,
XII.

8. ANTITHROMBIN ACTION OF FIBRIN &
ANTITHROMBIN III
During the formation of clot 80-90% of thrombin is
absorbed to the fibrin fibres and spread of clot is
prevented
Remaining thrombin combines with
Antithrombin III
Leading to  Blockage of effect of
Thrombin on fibrinogen.
Inactivation of Thrombin
itself.

9. THANK
YOU

10. THANK
YOU