Below the level of the heart, the movement of blood in the veins toward the heart is caused primarily by
A) gravity.
B) the contraction of venous walls.
C) cilia lining the veins.
D) the contraction of nearby skeletal muscles.
E) venous capacitance.

Question

Quizplus · Accepted Answer

The movement of blood in the veins toward the heart below the level of the heart is primarily due to the contraction of nearby skeletal muscles, which compress the veins and propel blood back toward the heart. This process is known as the skeletal muscle pump.

Below the Level of the Heart, the Movement of Blood