As blood travels through the venous system toward the heart, why do the veins become larger in diameter?

Question

Quizplus · Accepted Answer

The increase in diameter (or decrease in resistance) of veins as blood travels toward the heart allows for a decrease in pressure and an increase in flow rate. This is because the blood has already gone through the capillaries, which have a high resistance and slow down the flow rate. The larger diameter veins allow for a more efficient return of blood to the heart.

As Blood Travels Through the Venous System Toward the Heart