Which of the following does NOT assist in returning the blood to the heart through the veins? A. valves in the veins B. the “respiratory pump” C. the effect of gravity D. the pumping action of the heart
Option D. The pumping action of the heart does not assist in returning the blood to the heart through the viens. REASON:- The heart’s contractions do now no longer have an effect on blood movement after blood passes thru the capillaries. The contraction of the diaphragm, increases pressure withinside the stomach and this creates a pressure gradient that pushes blood closer to the heart towards gravity. Gravity assists blood to go back from the head and neck.
