Clotting of blood involves

Options

A. Hemolysis of RBCs
B. Denaturation of albumins by thrombin
C. Inactivation of plasma clotting factors
D. Change of fibrinogen to fibrin by thrombin

Answer

**Step-by-Step Solution:**

1. **Identify the Components Involved in Blood Clotting:**
- The primary cells involved in blood clotting are platelets. They play a crucial role in the initial response to blood vessel injury.

2. **Understand the Role of Calcium and Vitamin K:**
- Calcium ions are essential for various steps in the clotting process.
- Vitamin K is important for the synthesis of clotting proteins in the liver, which are necessary for the clotting cascade.

3. **Mechanism of Blood Clotting:**
- When a blood vessel is torn, collagen from the damaged vessel wall comes into contact with the blood.
- Damaged cells release phospholipids, and thromboplastin (a clotting factor) is released from both tissues and platelets.

4. **Formation of Platelet Plug:**
- Platelets aggregate at the site of injury and form a temporary plug to reduce blood loss.

5. **Activation of Clotting Proteins:**
- The tear in the blood vessel activates clotting proteins in the plasma.
- Prothrombin, an inactive protein, is converted into thrombin through the action of thrombokinase.

6. **Conversion of Fibrinogen to Fibrin:**
- Thrombin then converts fibrinogen (a soluble plasma protein) into fibrin (an insoluble protein).
- Fibrin forms long threads that weave through the platelet plug and trap blood cells, forming a stable blood clot.

7. **Conclusion:**
- The main process involved in blood clotting is the conversion of fibrinogen to fibrin by thrombin, which is activated from prothrombin.

**Final Answer:**
The clotting of blood primarily involves the conversion of fibrinogen to fibrin by thrombin.

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