Question

Which of these help in blood clotting?
A. Sodium
B. Bilirubin
C. Fibrinogen
D. None of the above

Answer 1

Hint: The mechanism present in the higher animal's body that helps to reduce or stop the blood flow after any injury.

Complete answer:
Blood clotting is an essential process where the coagulation cellular blood components take place in the place of an injury so as to prevent excessive blood flow.
Blood clotting is checked in the blood vessels by the presence of an anticoagulant. Fibrinogen protein which is present in cells is converted into fibrin to form a clot, in the presence of calcium ion and thrombin.

Additional Information:
Platelets (named because of their platelike flatness), or thrombocytes (Gr. thrombus, clot cells), are disk-shaped cell fragments that initiate blood clotting. When a blood vessel is injured, platelets immediately move to the site and clump, attaching themselves to the damaged area, and thereby beginning the process of blood coagulation.
Calcium (Ca) Component of bone and teeth; essential for normal blood clotting.
When an injury is caused to a blood vessel bleeding starts. So the four main stages are-
1. Damaged platelets or cells release thromboplastin which helps in the formation of thrombokinase.
2. Prothrombin present in the blood is then converted to thrombin by thrombokinase and calcium.
3. Thrombin then covers the fibrinogen to fibrin in the presence of calcium ions.
4. Then fibrin and the tissue cells form the blood clots.

So, the correct answer is ‘fibrinogen’

Note: Vitamin K is needed for the synthesis of prothrombin which is needed for blood clotting. The serum is plasma from which the proteins involved in blood clotting have been removed. Histamine causes blood vessels to dilate and leak fluid at a site of inflammation, and heparin prevents blood clotting. There are 9 coagulation factors present in the blood.