This paper identifies several published models of cardiovascular function, and attempts to analyze them in terms of the physiological processes which are embedded in their structure. It appears that representative models have increased in size and complexity in direct proportion to increases in the power and suitability of available computing machinery. An early focus on pulsatile hemodynamics within a single vascular compartment has evolved into analyses of ventricular filling and ejection, the function of the circulatory system as a closed system, longterm cardiovascular control, and the interaction of the circulatory system with other organ systems.