A circulation model for teaching fluid dynamics in laboratory courses in physiology

Summary. Medical students in Germany do not usually have a strong enough basis in physics to understand the mechanical and fluid dynamic problems involved in the physiology of the circulation. To alleviate this situation we developed a circulation model for use in laboratory courses in physiology. The following parameters can be varied: stroke volume, heart rate, systemic filling pressure, compliance of the arterial system (Windkessel), and total peripheral resistance. Arterial and venous pressure are recorded as a function of time. The following points are worked out by the students by adjusting the parameters of the model and by calculation: static equilibrium, transient and steady state in flow, compliance of the arterial and venous system, arteriovenous pressure difference, cardiac output, total peripheral resistance, regulation of cardiac output, pulse pressure amplitude, volume stored periodically in the arterial Windkessel, diastolic pressure decay of arterial pressure, diagnosis of arterial hypertension at different Windkessel compliances.