|6452||RESTLESS PUMP, THE||RESTLESS PUMP, THE||1992||color||24 min||vhs|| Looks at how the heart responds to demands from the tissues in a variety of physiological situations. During aerobic exercise, changes in the blood flow can be achieved not only by an increase in heart rate, but by a greater output from the heart at each beat. But dramatic changes in blood flow can occur without physical exercise and as an example. researchers simulate the G-induced effects of high-speed flight on the heart and circulatory system. Emotional stress can mimic the effects of physical exercise, increasing both heart rate and blood pressure.