Question

Which of the following helps in blood clotting?
A. Platelets
B. Red blood corpuscles
C. Monocytes
D. Lymphocytes

Answer 1

Hint: Blood clot is referred to as a clump of blood that has changed from a liquid state to a gel-like or semisolid state. Clotting is a necessary process that can prevent you from losing too much blood in certain circumstances, such as when you’re injured or cut. The human circulatory system is made up of vessels known as veins and arteries, which transport blood throughout our body. Blood clots are mainly formed in veins or arteries.

Complete answer: Coagulation begins almost instantly after an injury to the endothelium lining a blood vessel. Exposure of blood to the subendothelial space begins two processes that are-
1.Changes in platelets
2.The exposure of subendothelial tissue factor to plasma factor VII, which ultimately gives rise to cross-linked fibrin formation.
The mechanism of coagulation involves activation, adhesion, and aggregation of platelets, as well as deposition and maturation of fibrin. Coagulation begins almost instantly after an injury to the endothelium lining a blood vessel.
After that Platelets instantly form a plug at the site of injury and this is called primary hemostasis. Secondary hemostasis occurs simultaneously in which additional coagulation (clotting) factors beyond factor VII respond in a cascade to form fibrin strands, which strengthen the platelet plug. Platelets are small cell fragments that are found within our blood. The first and most important responsibility of the platelets is to stop the bleeding whenever the injury occurs to the body. A barrier called a blood clot must be formed to close the wound. And a damaged blood vessel must be blocked so that there is no excessive blood loss.
So, the correct option is option A-Platelets.

Note: The coagulation cascade of secondary hemostasis has two initial pathways that lead to fibrin formation. These are-
1.Contact activation pathway which is also known as the intrinsic pathway.
2.The tissue factor pathway which is also known as the extrinsic pathway.
They both lead to the same fundamental reactions that produce fibrin.