Word parts
What it means
The automatic control system of the body. It has two branches that mostly do opposite things. The sympathetic branch prepares the body for stress ("fight or flight"): a faster heart, wider airways and pupils, less digestion. The parasympathetic branch calms the body ("rest and digest"): a slower heart, more digestion and emptying of the bladder. Many drugs act on these branches.
Remember it
Sympathetic is fight or flight; parasympathetic is rest and digest.
At a glance
| Abbreviations | ANS |
|---|---|
| Spanish | sistema nervioso autónomo |
| Also written | ANS |
Related terms
central nervous system
The brain and the spinal cord together.
neurotransmitter
A chemical that a nerve cell releases to pass a signal to another nerve, muscle or gland cell.
peripheral nervous system
All the nerves outside the brain and spinal cord, which link them to the rest of the body.