Neural control of the cardiovascular system during exercise. An integrative role for the vestibular system.

Precise regulatory signals are required in order to adjust the cardiovascular and respiratory systems to meet the demands of exercise. Two neural mechanisms, central command and a reflex originating in contracting muscles, are known to play a large role in exercise-associated adjustments in cardiovascular and respiratory activity. The extent to which other regulatory reflexes, such as vestibulo-autonomic reflexes, are able to impact upon the cardiovascular and respiratory systems during exercise is largely unknown. Further, brain regions that may integrate these control mechanisms are only starting to be investigated. We propose that medullary brain nuclei may integrate both exercise and vestibular signals to produce a more coordinated, and therefore efficient, means of adaptation to exercise in a gravitational environment.