BLOOD CLOTTING -

• It is a nature's device to check the excessive loss of blood from an injury.
• Bleeding time is 1-3 minutes. Clotting time is 2-6 minutes.
• Process of clotting is initiated by platelets / Thrombocytes.
• After clotting remaining part is serum. Clotting is a bio-chemical reaction, explained by Hobel.
• Clotting theory is given by cascode. Vit. K is necessory for clotting.
• In haemophillia (sex-linked inheritance) VIII factor is absent so injection of AHG (Anti haemophilic globulin) are given.
• At the point of injury serotonine & thromboplastin (lipoprotein) are released.
• Serotonine is helpful in vaso constriction. Thromboplastin helps in the formation of prothrombinase.
• In presence of prothrombinase prothrombin is converted into thrombin.
• Thrombin reacts with fibrinogen in presence of air & Ca++ to form fibrin. Network of fibrin forms clot.
• In presence of XII factor (Hagmen factor / glycoprotein) danse net is formed.