If blood flow through the afferent arterioles increases,
A) stretch reflexes trigger vasoconstriction to reduce the flow.
B) the smooth muscle in the vessel walls stretches to accommodate the increased flow.
C) the stretch triggers further relaxation of the arteriolar wall, lessening blood pressure.
D) the smooth muscle in the vessel walls stretches to accommodate the increased flow and the stretch triggers further relaxation of the arteriolar wall, lessening blood pressure.

Question

Quizplus · Accepted Answer

Stretch reflexes trigger vasoconstriction to reduce the flow in order to maintain stable blood pressure and prevent excessive blood flow to the capillaries. This is known as autoregulation of blood flow. Option B is incorrect as the smooth muscle does not stretch to accommodate increased flow but rather contracts. Option C is incorrect as the stretch triggers further vasoconstriction, thereby increasing blood pressure. Option D is incorrect as the smooth muscle does not relax in response to increased flow but contracts.

If Blood Flow Through the Afferent Arterioles Increases