Decreased ECF volume causes
A) sympathetic output from the cardiovascular control center to increase.
B) parasympathetic output from the cardiovascular control center to increase.
C) the force of ventricular contraction to decrease.
D) arteriolar vasodilation.
E) sympathetic output from the cardiovascular control center to increase and arteriolar vasodilation.

Question

Quizplus · Accepted Answer

Decreased ECF volume (such as from dehydration or blood loss) leads to a decrease in blood pressure. To compensate for this, the sympathetic output from the cardiovascular control center increases, causing vasoconstriction and an increase in heart rate and contractility to maintain blood pressure. Parasympathetic output would not increase in this situation. The force of ventricular contraction may increase, not decrease, in response to sympathetic activation. Arteriolar vasoconstriction, not vasodilation, is the typical response to sympathetic activation in order to maintain blood pressure.

Decreased ECF Volume Causes