If a person has lost a significant amount of blood but still maintains a normal blood pressure it does not necessarily mean that the person is maintaining adequate perfusion. Which of the following best explains why this is so?
a. Blood vessels are constricting causing greater peripheral resistance.
b. The heart has increased its rate to increase cardiac output.
c. The sympathetic nervous system has increased its nerve impulses.
d. The heart has increased its contractile force increasing cardiac output.

a. Blood vessels are constricting causing greater peripheral resistance.

Explanation:

Peripheral vascular resistance means the resistance in the circulatory system that is used to control blood pressure and the flow of blood. When blood vessels constrict, there would be an increase in systemic vascular resistance. When blood vessels dilate, there would be a decrease in systemic vascular resistance.

a. decomposes use carbon from dead organisms as fuel for cellular respiration, returning carbon dioxide back into the atmosphere.