Which of these statements describes vasoconstriction
A)It causes a decrease in resistance.
B)It occurs when there is a decrease in the radius of a vessel.
C)It is due to a decrease in sympathetic activity.
D)It causes no change in resistance.

Question

Quizplus · Accepted Answer

Vasoconstriction is the narrowing of the blood vessels due to the contraction of the smooth muscles in their walls. This results in a decrease in the radius of the vessel, which leads to an increase in resistance to blood flow. Therefore, choice B is the correct statement. A is incorrect because vasoconstriction causes an increase in resistance. C is incorrect because vasoconstriction is typically caused by an increase in sympathetic activity. D is incorrect because it causes an increase in resistance.

Which of These Statements Describes Vasoconstriction