<unk>  is the study of the<unk>  system, specifically addressing the physiology of the heart ("cardio") and blood vessels ("vascular"). These subjects are sometimes addressed separately, under the names cardiac physiology and circulatory physiology. Although the different aspects of<unk>  are closely interrelated, the subject is still usually divided into several subtopics.
Cardiovascular physiology
Cardiac cycle
Hemodynamics
Gastrointestinal physiology
Renal physiology
Cardiac reserve
Muscle tone
Myogenic tone