Body Fluids and Circulation Question 70
70. Which of the following substances, if introduced into the blood stream, would cause coagulation of blood at the site of its introduction?
(a) Prothrombin
(b) Fibrinogen
(c) Thromboplastin
(d) Heparin
Show Answer
Answer : c
Hints & Solutions
(c) Fibrinogen, prothrombin, thromboplastin are respectively clotting factors I, II and III. Thromboplastin is released from injured platelets or injured tissue. This converts prothrombin into thrombin in the presence of calcium ions. The thrombin converts fibrinogen into fibrin and the latter froms the clot.
