GENERAL HISTOLOGY

Detailed explanation-1: -They involve both the circular muscles that ring the tubes of your digestive tract and also longitudinal muscles that span the walls of the tubes. The circular muscles squeeze and expand in a synchronized way to push the food through the tube while the longitudinal muscles propel everything forward.

Detailed explanation-2: -The large, hollow organs of the GI tract contain a layer of muscle that enables their walls to move. The movement of organ walls-called peristalsis-propels food and liquid through the GI tract and mixes the contents within each organ.

Detailed explanation-3: -Infection, usually from a virus. Certain medications that slow the rate of stomach emptying, such as narcotic pain medications. Scleroderma-a connective tissue disease. Nervous system diseases, such as Parkinson’s disease or multiple sclerosis.

Detailed explanation-4: -The parasympathetic nervous system (PNS) stimulates peristalsis via the myenteric plexus. The afferent (sensory) nerves of the myenteric plexus deliver information to interneurons within the plexus. Interneurons communicate with efferent nerves, stimulating an action potential (spike-wave) within smooth muscle cells.

Detailed explanation-5: -Peristaltic waves push the swallowed bolus down the esophagus. In the stomach, peristalsis churns swallowed food, mixing it with gastric juices. These mechanical and chemical actions further break down food into a substance called chyme.