Parasympathetic nervous system

Definition

The parasympathetic nervous system is a division of the autonomic nervous system that promotes 'rest-and-digest' activities. It works to conserve energy by slowing the heart rate and increasing intestinal and gland activity.

5 Must Know Facts For Your Next Test

1. The parasympathetic nervous system is primarily responsible for stimulating digestion, activating metabolism, and helping the body to relax.
2. It operates through neurotransmitters like acetylcholine to carry out its functions.
3. The vagus nerve is a major component of the parasympathetic nervous system, extending from the brainstem to various organs in the body.
4. Parasympathetic responses are usually involuntary and occur without conscious control.
5. It counterbalances the actions of the sympathetic nervous system, which prepares the body for 'fight-or-flight' situations.

Review Questions

• What primary neurotransmitter does the parasympathetic nervous system use?
• Which major nerve is associated with the parasympathetic nervous system?
• How does the parasympathetic nervous system affect heart rate?

Related terms

Sympathetic Nervous System: A division of the autonomic nervous system that prepares the body for 'fight-or-flight' actions.

Autonomic Nervous System: A part of the peripheral nervous system that controls involuntary bodily functions like heartbeat and digestion.

Vagus Nerve:

A critical nerve in the parasympathetic nervous system that extends from the brainstem to various organs in the chest and abdomen.