What is the parasympathetic nervous system?

The parasympathetic nervous system (PNS) is the main division of the autonomous nervous system that controls the function of the body organs of the body, blood vessels and smooth muscles. While most of the actions of the parasympathetic nervous system are automatic and involuntary, some like breathing work in accordance with a conscious mind. When PNS is largely considered to be a control system, if external conditions are calm and normal, supports slower heart rhythm, slower respiratory frequency, increased sweating and salivation, smaller pupils, improved waste disposal and sexual excitement. Unlike the other division of the autonomous nervous system, a sympathetic nervous system that mediates the response of "fighting or flight" works when conditions do not require immediate action in response "digest and rest". In a complex homeostatic process, sympathetic and parasympathetic systems have contradictory, but in common ways, similar to the accelerator and the brakeutomobil to maintain the vital function of the body balanced.

All parasympathetic nervous systems consist of backbone and cranial segments. Near the tail bone or cross bone comes from the second, third and fourth sacral nerves that innervate the pelvic organs. The brain is based on a parasympathetic system of four skull nerves: oculomotor nerve, face nerve, glossopharyngeal nerve and vagus nerve. All PNS segments consist of sensory components that transmit information to the brain, and motor components that provide appropriate feedback to the final organs. Sensory cells monitor blood pressure, oxide and carbon dioxide levels, blood sugar concentrations and stomach and intestine content, while motor neurons, grouped into small ganglia near the target organs, modulate the body's reactions to sensory cells.

acetylcholin needle chemical messenger relaxed in neuronal intersections of parasympathetic nerveHO system. Muscarinic receptors, which are thus named because of their sensitivity to muscarin from the mushroom Amanita Muscaria, are the main end receptors PN. Molecules of acetylcholine activate muscarin receptors in plasma membranes of nerve cells by connecting with intracellular proteins. Once acetylcholin is bound to proteins, the cascade of events leads to the reaction of the final organ. Scientists have discovered five subtypes of muscarin receptors, each of which had a different gene.

Dysautonomy concerns the dysfunction of the autonomic nervous system, where a sympathetic or parasympathetic nervous system has a disproportionate effect on the body. Viral infections, toxic exposures, trauma and inheritance were implicated as causal factors for this condition. Symptoms include pain and pain, fainting of magic, fatigue, anxiety attacks, fast Eart hem and low blood pressure. Examination of patients with dysautonomy usually provides doctors, if at all, objective physical or laboratory findings. There is noA widely accepted approach to treatment for dysautonomics and therapeutic experiments are largely aimed at alleviating symptoms, not cure of dysfunction.