The<unk>  The<unk>  is a collection of<unk><unk> s that aid the heart in the circulation of blood. It is especially important in increasing venous return to the heart, but may also play a role in arterial blood flow.
Skeletal-muscle pump
Cardiac cycle
Lymphatic pump
Autonomic nervous system
Parasympathetic nervous system
Myogenic tone
Myocardial contractility
Muscle tone