Figure 10.

Demonstration in chronically instrumented dogs of baroreceptor resetting during exercise. This record was generated in animals that had undergone isolation of the carotid sinuses, permitting pressure in the carotid sinus to be controlled independently of arterial pressure. The input was carotid sinus pressure (x-axis); the output was systemic pressure measured in the whole animal (y-axis). During exercise, baroreceptor regulation of heart rate was reset to defend a higher arterial pressure, but the stimulus response curve to a given change in pressure was similar. Exercise was performed while running on a treadmill at 5.5 km/h up either a 7 or 21% grade. [Adapted from Joyner (237).]