Tag: blood clotting and healing of wounds

Blood-clotting proteins circulate in the blood plasma in an inactive form, poised to participate in blood coagulation upon tissue injury. Blood-clotting proteins generate thrombin, an enzyme that converts fibrinogen to fibrin, and a reaction that leads to the formation of a fibrin clot.

Prothrombin is a coagulation or clotting factor that is needed for the normal clotting of blood. A cascade of biochemical events leads to the formation of the final clot. In this cascade, prothrombin is a precursor to thrombin.
Prothrombin is produced in the liver and is modified in the presence of vitamin K.
Therefore, the correct answer is option A.

Platelets are components of blood. They prevent bleeding by activating coagulation mechanisms hence contribute in wound healing. They play an important role in inflammatory and proliferative events. If the platelets are not present in the blood there will be continuous loss of blood by the blood vessels which may prove fatal.

Sodium oxalate acts as an anticoagulant. Sodium oxalate inhibits blood coagulation by forming an insoluble complex with calcium because calcium is a cofactor that involves in the clotting process. Hence, option A is the correct answer.

Fibrinogen is a glycoprotein that helps in the formation of blood clots.
Thrombin is a blood coagulation factor.

Fibrinogen is factor I and its source is liver. When fibrinogen is converted into fibrin by thrombin, it forms long strands, that compose the mesh network for clot formation.
Calcium is factor IV and its source is bone and absorption from food in gastrointestinal tract. It works with many clotting factors for activation of the other clotting factors.
Vitamin K is an essential factor to various protein enzymes, that are a part of coagulation cascade.
Vitamin D is found in fish and liver oil and is essential for absorption of calcium.
Thus, the correct answer is option B.

Coagulation is the process by which the blood changes from a liquid to a gel-like form. Blood plasma will coagulate, as, it has clotting factors in it and fibrinogen protein.
Serum will not coagulate, as, it do not have any clotting factors and fibrinogen.
Lymph is more like blood plasma, so, contains clotting factors and will coagulate.
Whole blood obviously coagulate for containing the same above factors.
Thus, the correct answer is option (B).

Factor VIII is an important blood clotting protein, which is also known as anti-haemophilic factor (AHF), encoded by the F$ _{8}$ gene.
Factor VIII circulates in the bloodstream in an inactive form, bound to another molecule, called Von Willebrand factor, until an injury that damages the blood vessels occurs. When injury occurs, the factor VIII is activated and separates from Von Willebrand factor. The active protein interacts with another coagulation factor, called factor IX. This interaction leads to a chain of additional reactions, that form a blood clot.

When there is an injury and blood is shed, the platelets disintegrate and liberate thromboplastin or factor III. Certain amount of thromboplastin is also derived from the damaged tissues of the injured locality.
Thromboplastin converts prothrombin into thrombin with the help of calcium ions and thrombin interacts with fibrinogen forming fibrin. This is clot.
Calcium is the Factor IV and it acts as a co-factor in the coagulation process.
Thus, the correct answer is option (B).