Question

Boojho was learning to ride a bicycle. He lost his balance and fell down. However, it was observed that the bleeding stopped after some time.

1. Give the reason for the bleeding to stop?
2. Of what color would the wounded area be and why?
3. Blood clotting occurs as a result of which blood cells?

Answer 1

Blood Clotting

1. Blood clotting or the coagulation of blood is a mechanism that prevents immense bleeding when an injury of a blood vessel occurs.

1. A mass of blood that is formed when cells, platelets, and proteins in the blood stick together after an injury is known as a blood clot or thrombus.
2. Blood clotting involves several steps:

• The first is the release of prothrombin from the platelets at the site of injury.
• The prothrombin gets activated to thrombin.
• This thrombin splits fibrinogen to fibrin.
• A mesh is formed by the fibers of fibrin leading to the stopping of bleeding.
• The clot becomes hard and diminishes.
• New cells are generated at the site of the clot.
• The clot is dissolved by plasmin enzymes.

Formation of a Blood clot:

1. The bleeding stopped in case of Boojho's injury due to the formation of a blood clot.
2. The color of the wounded area would be dark red due to clotting and accumulation of red blood corpuscles (RBC).
3. The type of blood cells which are responsible for clotting blood are platelets. They promote the formation of blood clots.