Navin Kumar B. answered 02/28/23
Anatomy tutor with both research and teaching experience
The correct answer is E, only b & c.
During exercise, venous return is enhanced by the operation of the respiratory muscle/ventilation pump and the skeletal muscle pump.
The respiratory muscle/ventilation pump works by creating negative pressure in the thoracic cavity during inhalation, which helps to pull venous blood back towards the heart. During exhalation, the pressure in the thoracic cavity increases, which helps to push blood out of the veins and towards the heart.
The skeletal muscle pump works by the rhythmic contraction and relaxation of skeletal muscles, which helps to squeeze blood in the veins towards the heart. As the muscles contract, they compress the veins, which increases the pressure and helps to push blood towards the heart. As the muscles relax, the veins are allowed to fill with blood, which reduces pressure and creates a vacuum that helps to pull more blood towards the heart.
The operation of carotid arterial and femoral arterial valves is not directly involved in enhancing venous return during exercise.