Question

multiple choice question
what is the first response to a blood vessel injury?

o platelet plug formation
o vasodilation
o blood clot formation
o vascular spasm

Explanation:

When a blood - vessel is injured, the first event is the constriction of the blood vessel, which is called a vascular spasm. This reduces blood flow to the injured area. Platelet plug formation and blood - clot formation occur later in the hemostasis process. Vasodilation is the opposite of what happens initially; it would increase blood flow rather than reduce it at the site of injury.

Answer:

Vascular spasm