parasympathetic

The parasympathetic division of the autonomic nervous system is often called the "rest and digest" system. In the cardiovascular system, parasympathetic nerve signals carried by the vagus nerve to the pacemaker cells of the heart slow the heart rate by decreasing the rate of phase 4 depolarization.

See also: sympathetic division.

Guyton online medical physiology textbook

See: autonomic regulation of cardiovascular function in the Dale Purves Neuroscience textbook.