How do the parasympathetic nerves control muscles

The parasympathetic nervous system is very important to our body. For example, our body's stress response is completed through the parasympathetic nervous system. Parasympathetic nerves are widely distributed in our internal organs, limbs, blood vessels and glands. If there is a problem with the parasympathetic nervous system, the muscles and tissues it controls will react accordingly. For example, abnormalities in the parasympathetic nerves of the blood vessels can affect blood circulation, and abnormalities in the gastrointestinal parasympathetic nerves can affect our digestive function.

The parasympathetic nervous system is part of the autonomic nervous system and is divided into the brain and sacral regions. The brain center is located in the cerebrum, collectively known as the parasympathetic nucleus, which sends fibers running through the 3rd, 7th, 9th, and 10th cranial nerves. The peripheral ganglia include para-organ ganglia and internal organ ganglia. Among them, the para-organ ganglia located in the skull are larger and visible to the naked eye. The preganglionic fibers of the cranial parasympathetic nerves send out postganglionic fibers to the organs they control after exchanging neurons here. The sacral center is located in the intermediolateral sacral nucleus in the gray matter of segments 2 to 4 of the sacral cord. It sends preganglionic fibers to the paraganglia near the organs and the internal ganglia in the organ walls, forming the pelvic nerve, which innervates the digestive tract below the descending colon, pelvic organs, and external genitalia. Stimulating the parasympathetic nerves can cause reactions such as slowing of the heart rate, increased secretion of digestive glands, pupil constriction, and bladder contraction. The function of the parasympathetic nervous system is mainly to maintain physiological needs during quiet times.

The functions of the parasympathetic nervous system are opposite to those of the sympathetic nervous system. Although it is not as consistent as the sympathetic nervous system, it is also quite related. Its fibers are not distributed in the limbs, but the erector muscles of the sweat glands, adrenal glands, thyroid gland, uterus, etc. have parasympathetic nerve distribution sites. The parasympathetic nervous system can maintain the body's physiological balance in a quiet state. Its functions have three aspects: enhancing gastrointestinal activity, the secretion of digestive glands, promoting the excretion of urine and feces, and maintaining the body's energy. The pupils constrict to reduce stimulation and promote the production of glycogen in the liver to store energy. The heartbeat slows down, blood pressure drops, and bronchi narrow to save unnecessary consumption and assist reproductive activities, such as dilating reproductive blood vessels and increasing secretions of sexual organs.

Through the above introduction, everyone must know the parts of the body controlled by the parasympathetic nervous system. Since the parasympathetic nervous system has a great influence on our body, and various external stimuli can easily affect the parasympathetic nervous system, we must avoid parasympathetic nervous system dysfunction in our lives. For example, you should keep your emotions stable at ordinary times, ensure adequate sleep, don't be pessimistic or disappointed, and don't be sensitive or suspicious.