Factors affecting venous return:
(1) The driving force of venous return is the pressure difference at both ends of the vein, that is, the difference between peripheral venous pressure and central venous pressure. The formation of the pressure difference mainly depends on the contractile force of the heart, but it is also affected by respiratory movement, body position, muscle contraction, etc.
(2) Skeletal muscle compressions act as muscle pumps to promote venous return |.
(3) Respiratory movement affects venous return by affecting intrathoracic pressure.
(4) When the human body changes from lying position to standing position, the amount of blood returned to the heart is reduced.
