The parasympathetic division is a part of the autonomic nervous system that helps the body relax and conserve energy. It is often referred to as the "rest and digest" system because it promotes functions that occur when the body is at rest, such as slowing the heart rate and stimulating digestion. This division works by releasing neurotransmitters like acetylcholine, which signal various organs to perform their functions more efficiently. For example, it enhances the activity of the gastrointestinal tract and reduces the body's stress response, allowing for recovery and maintenance of bodily functions.