Cardiovascular interactions: an interactive tutorial and mathematical model.

The maintenance of an adequate cardiac output and systemic arterial blood pressure is a complex process with intricacies that are often difficult to understand. Cardiovascular Interactions is an active learning tool that demonstrates the interactions between the functions of the heart and peripheral circulation. This learning package consists of a Lab Book, a Model, and an Information file. The Lab Book is an interactive tutorial for exploring the relative influences of parameter changes on the cardiovascular system under normal, stressful, or pathophysiological conditions. The learners are guided to predict the direction and relative magnitude of changes of key variables in the cardiovascular system, evaluate the accuracy of their predictions, and describe the cause-and-effect mechanisms involved. Consequences of heart failure, hemorrhage, exercise, and changes in intrathoracic pressure can be explored. The results obtained in the Lab Book are based on a five-compartment mathematical Model, which reflects our current understanding of the basic control of the cardiovascular system. The Model was designed to be complex enough to be realistic, yet not so complex as to be overwhelming. An Information File contains definitions and descriptions of classical physiology about key concepts, including figures, and a detailed description of the Model. Hypertext tags embedded in the Lab Book are used to access the Information File. The Cardiovascular Interactions learning package was designed to run from its CD and so does not need to be installed.