Cardiac and respiratory rhythmicities in cutaneous and muscle vasoconstrictor neurones to the cat's hindlimb.

Cardiac and respiratory rhythmicities have been investigated quantitatively in postganglionic vasoconstrictor neurones supplying skeletal muscle and skin of the hindlimb in chloralose anesthetized, immobilized cats. Both rhythmicities are largest in muscle vasoconstrictor neurones, smaller in vasoconstrictor neurones supplying hariy skin, and smallest in vasoconstrictor neurones supplying hairless skin. The magnitude of the cardiac rhythmicity in the vasoconstrictor neurones is positively correlated with the quantitative reaction to systemic hypoxia.