Systemic vascular resistance decreases when the
A)blood viscosity increases.
B)stroke volume increases.
C)arterioles dilate.
D)arterioles respond to sympathetic nerve stimulation.

Question

Quizplus · Accepted Answer

Arterioles are the smallest resistance vessels in the body, and when they dilate, there is less resistance to blood flow in the systemic circulation. This causes a decrease in systemic vascular resistance. Conversely, when arterioles constrict, systemic vascular resistance increases. Blood viscosity (A) actually increases resistance, while an increase in stroke volume (B) can increase vascular resistance due to increased blood flow. Sympathetic nerve stimulation (D) can cause vasoconstriction, resulting in increased resistance.

Systemic Vascular Resistance Decreases When the