parasympatískt

Parasympatisk refers to a division of the autonomic nervous system, often called the "rest and digest" system. It works in opposition to the sympathetic nervous system, which is associated with the "fight or flight" response. The parasympathetic nervous system is primarily responsible for conserving energy and promoting bodily functions during periods of rest.

The main neurotransmitter of the parasympathetic nervous system is acetylcholine. It acts on various organs to slow the heart rate, increase intestinal and gland activity, and relax sphincter muscles. Key nerves associated with the parasympathetic system include the vagus nerve, which has widespread influence throughout the body, and cranial nerves III, VII, IX, and X, as well as sacral spinal nerves.

Activation of the parasympathetic system leads to a range of physiological effects. These include pupil constriction, salivation, reduced heart rate and blood pressure, increased digestion and absorption of food, stimulation of urination and defecation, and general relaxation. In essence, it helps the body return to a state of calm and homeostasis after a stressful event or during periods of inactivity. Understanding the parasympathetic nervous system is crucial for comprehending how the body regulates essential involuntary functions.