19. what would occur if the muscle tissue failed within a damaged blood vessel?

a. vascular spasm would not occur, resulting in excessive blood loss.
b. coagulation would not occur, preventing fibrin formation.
c. platelet aggregation would not occur, preventing plug formation.
d. endothelial cell division would not occur, preventing wound healing.

A. Vascular spasm would not occur, resulting in excessive blood loss.

Explanation:

The walls of blood vessels consist of smooth muscles to perform involuntary contraction to support the pumping of blood. Any damage to blood vessels results in sudden contraction of smooth muscles and is called as vascular spasm. The vascular spasm serves to constrict the blood flow so as to prevent blood loss. If smooth muscles do not work, vascular spasm would not occur leading to excessive blood loss.