Part of the autonomic nervous system that regulates internal organs and involuntary functions like heart rate and blood pressure; it works in opposition to the [[副交感神经|副交感神經|fu4 jiao1 gan3 shen2 jing1]]

the part of the autonomic nervous system that slows the heart rate and relaxes muscles, operating in opposition to the sympathetic nervous system

the process by which one system or organ responds to a change in another, as in physical adaptation or sympathetic nerve function