Parasympathetic Nervous System
The parasympathetic nervous system is a branch of the autonomic nervous system. Parasympathetic fibers originate in the brain and sacral spinal cord and innervate mainly internal organs.
The parasympathetic nervous system, together with the sympathetic nervous system, forms the autonomic (autonomic) nervous system, which regulates the functioning of internal organs, glands, blood vessels and other structures of the body.
Unlike the sympathetic nervous system, which mobilizes the body for vigorous activity, the parasympathetic system, on the contrary, ensures relaxation of organs and tissues and a decrease in metabolic processes. It is activated during rest and sleep.
Parasympathetic fibers innervate the heart, lungs, digestive system, genitourinary organs and other internal organs. Their activation leads to a slowdown in the heartbeat, dilation of the bronchi and blood vessels, increased intestinal motility, salivation and other effects.
Thus, the parasympathetic nervous system complements and balances the actions of the sympathetic system, ensuring homeostasis and optimal functioning of the internal organs.