Marco falls off his bicycle and injures his ankle. Which of the following actions shows the initial response to the injury in the extrinsic pathway?
A. Release of Calcium
B. Release of tissue thromboplastin
C. Conversion of factors XII to factor XIIa
D. Conversion of factor VIII to factor VIIIa
Correct Answer: B. Release of tissue thromboplastin
Tissue thromboplastin is released when damaged tissue comes in contact with clotting factors.
Option A: Calcium is released to assist the conversion of factors X to Xa.
Option C: Conversion of factors XII to XIIa are part of the intrinsic pathway.
Option D: Conversion factors VIII to VIIIa are part of the intrinsic pathway.