The cardiovascular system is a central topic in physiology classes, yet it is difficult to provide undergraduates with quality laboratory experiences in this area. Thus a model circulatory system was developed to give students hands-on experience with cardiovascular fluid dynamics. This model system can be constructed from readily available materials at a reasonable cost. It has a realistic pressure drop across the different vessels. Using this system, students can investigate the effect that blood volume, vessel compliance, vessel constriction, and heart activity have on blood pressure and flow. The system also demonstrates the effect of vessel diameter on resistance and fluid velocity. This model may give students a more concrete, intuitive feel for cardiovascular physiology. Another advantage is that it allows dramatic and easily controlled manipulations with quantitative results. Finally, its simple construction allows students to interchange components, giving them greater flexibility in experimentation.AM. J. PHYSIOL. 277 (ADV. PHYSIOL. EDUC. 22): S92-S99, 1999.