Question

Coagulation of blood is an important mechanism. Explain its mechanism.

Answer 1

Hint Blood is a fluid present in humans. It is necessary and delivers certain nutrients and oxygen to the cells and transport metabolic waste products away from those same cells.

Complete answer:
When the endothelium is damaged coagulation is done by the platelets and the collagen which is under it is exposed to the circulating platelets that bind to the collagen directly and collagen-specific glycoprotein at the surface receptors. They release the contents of stored granules in the blood plasma which includes serotonin, ADP, and a platelet-activating factor which activates additional platelets. The activation of the platelets is done by a platelet-activating factor which changes the shape of the platelets from spherical to stellate. It cross-links with the glycoprotein of the adjacent platelets. The secondary hemostasis consists of two initial pathways which lead to fibrin formation and the intrinsic pathway are the contact activation pathway which leads to the same fundamental reactions that produce fibrin. Serine proteases are the population factors that circulate as inactive zymogens and act by cleaving downstream proteins. The vasoconstriction is the body's first response to the injury in the vascular wall and causes reduced blood flow to the site of injury which involves the primary hemostasis. The aggregation of the platelets to the site of injury where they stick together acting as a plug is known as the platelet plug and activates the process which causes fibrin to form a clot known as secondary hemostasis.

Additional information:
Platelets are not enough to secure the damage of The vessel wall and a clot must have formed at the site of injury which depends upon several substances called clotting factors. They are designated by Roman numerals from I to XII which activate each other and are known as clotting cascade. This cascade results in fibrinogen which is a soluble plasma protein that is cleaved into fibrin and a non-soluble plasma protein. These cascades stick together to form a clot and occur through two pathways that interact with the intrinsic and extrinsic pathways.

Note: Platelets are essential for stopping bleeding and are produced in our bone marrow from large bone marrow cells known as megakaryocytes. 10% of donations constitute a special group of platelet donors. A blood drop contains 1,5000,000-4,000,000 platelets. Platelet transfusions help the patient with blood diseases and cancer to control bleeding after severe surgery and trauma.