Contraction of the muscles surrounding an arteriole that decreased its diameter by 50% would
A)increase the resistance in the arteriole approximately 16 fold.
B)decrease the resistance in the arteriole approximately 16 fold.
C)increase the resistance in the arteriole by approximately 50%.
D)decrease the resistance in the arteriole approximately 50%.
E)not be expected to change resistance in the arteriolE.

Question

Quizplus · Accepted Answer

Resistance is inversely proportional to the fourth power of the radius of the vessel. Therefore, if the radius decreases by 50%, the resistance will increase approximately 16 fold (or 2 to the power of 4). The contraction of the muscles in the arteriole would lead to vasoconstriction and decrease the diameter of the arteriole, which would result in an increase in resistance.

Contraction of the Muscles Surrounding an Arteriole That Decreased Its