GENERAL HISTOLOGY

Detailed explanation-1: -The vagus nerve, CN X, makes up about 75% of the PNS and provides parasympathetic input to most of the thoracic and abdominal viscera, with the sacral parasympathetic fibers innervating the descending and sigmoid colon and rectum. The vagus nerve has four cell bodies in the medulla oblongata.

Detailed explanation-2: -The autonomic nervous system Autonomic nervous system is the part of the nervous system that supplies the internal organs, including the blood vessels, stomach, intestine, liver, kidneys, bladder, genitals, lungs, pupils, heart, and sweat, salivary, and digestive glands.

Detailed explanation-3: -Medulla oblongata: The medulla oblongata is at the bottom of the brain stem, where the spinal cord meets the foramen magnum of the skull. It is responsible for autonomic functions, some of which are crucial for survival. The medulla oblongata monitors the bodies respiratory system using chemoreceptors.

Detailed explanation-4: -The term autonomic nervous system (ANS) refers to collections of motor neurons (ganglia) situated in the head, neck, thorax, abdomen, and pelvis, and to the axonal connections of these neurons (Figure 1).