Parasympathetic nervous system

The parasympathetic nervous system is one of the two main divisions of the autonomic nervous system, with the other being the sympathetic nervous system. The parasympathetic division is responsible for promoting relaxation, rest, and the body’s normal maintenance functions. It often acts in opposition to the sympathetic division, which prepares the body for “fight or flight” responses.

The “rest and digest” response refers to the physiological state that the parasympathetic nervous system promotes. When the parasympathetic division is activated, it helps conserve and restore energy by slowing down many bodily processes and facilitating digestion, nutrient absorption, and elimination. Some key features of the “rest and digest” response include:

Slowing of Heart Rate: The parasympathetic nervous system decreases heart rate, allowing the heart to work more efficiently and conserving energy.
Lowering Blood Pressure: By relaxing blood vessels and reducing constriction, the parasympathetic system helps lower blood pressure.
Increased Digestion: Activation of the parasympathetic system stimulates the digestive system by increasing saliva production, promoting peristalsis (contractions) in the gastrointestinal tract, and increasing digestive enzyme secretion.
Enhanced Nutrient Absorption: The parasympathetic response facilitates the absorption of nutrients from the digestive tract into the bloodstream, optimizing the body’s utilization of ingested food.
Increased Intestinal Motility: Peristalsis, the rhythmic contractions of the intestines, is heightened during the “rest and digest” response, aiding in the movement of food through the digestive system.
Stimulation of Urination and Defecation: The parasympathetic system promotes the relaxation of urinary and anal sphincters, facilitating the elimination of waste products.
Pupil Constriction: Activation of the parasympathetic division causes the pupils to constrict, which improves near vision and depth perception.

Overall, the parasympathetic nervous system’s “rest and digest” response helps create a state of relaxation, allowing the body to conserve energy, repair tissues, and perform necessary maintenance functions. It is essential for overall well-being and optimal physiological functioning.