question_answer

Which of the following substances, if introduce the blood stream, would cause coagulation at the site of its introduction?

A)  Fibrinogen                        

B)  Prothrombin

C)  Heparin                              

D)  Thromboplastin

Correct Answer: D

Solution :

Thromboplastin is a membrane glycoprotein found in tissue cells. When tissue is damaged, this forms a ca2+. Surface complex that, with phospholpid and converts a plasma glycoprotein, factor X to factor Xa, which in turn converts prothrombin in the blood to its enzymatically active form thrombin. Trrombin catalyses the formation of the insoluble protein fibrin from soluble fibrinogen, the fibrin form a fibrous network, in which blood cells become ennurished, producing a clot, ie, blood clotting or blood coagulation takes place.