Question

A superficial puncture wound from a needlestick injury leads to a small amount of bleeding in a healthy person. Seconds after this injury occurs, the bleeding stops. Which of the following mechanisms is most likely to stop small arteriolar blood loss from this injury?
a. Fibrin polymerization
b. Neutrophil chemotaxis
c. Platelet aggregation
d. Protein C activation
e. Vasoconstriction

Answer 1

Answer:

Vasoconstriction.

Explanation:

In order to prevent excessive blood loss or to cut shut blood flow from injured blood vessels  the  smooth muscles on the  walls of  large arteries   and veins usually   undergo involuntary contraction, so that the sizes of  diameter is decreased, and therefore blood loss is stopped.

This natural blood loss preventing mechanism is called Vasoconstriction.It can be triggered by both external and internal factors, but coordinated by combination both  hormonal and nervous system.

Answer 2

Answer:

E. Vasoconstriction.

Explanation:

Vasoconstriction is narrowing or constriction of the blood vessels. It happens when smooth muscles in blood vessel walls tighten. This makes the blood vessel opening smaller. Vasoconstriction may also be called vasospasm.

Vasoconstriction is a normal process. It helps keep your body in healthy balance.

Vasoconstriction may occur to:

stabilize blood pressure or raise blood pressure

reduce loss of body heat in cold temperatures

control how blood is distributed throughout your body

send more nutrients and oxygen to organs that need them

protect your body against blood and fluid loss