Blood return to the heart through the veins is aided by
A)a blood pressure difference from arteries to the capillaries.
B)skeletal muscle and respiratory pumps.
C)precapillary sphincters.
D)All apply.

Question

Quizplus · Accepted Answer

Blood return to the heart through the veins is aided by skeletal muscle and respiratory pumps, which help push the blood against gravity and through the one-way valves in veins. The blood pressure difference from arteries to capillaries helps drive the exchange of nutrients and waste products, but is not directly involved in aiding blood return to the heart. Precapillary sphincters are located in capillaries and help regulate blood flow to different tissues, but are also not directly involved in blood return to the heart.

Blood Return to the Heart Through the Veins Is Aided