THORAX ABDOMEN AND PELVIS

Detailed explanation-1: -The stomach: At the end of the esophagus is a muscular ring or valve called a sphincter (SFINK-ter). The sphincter lets food enter the stomach, then squeezes shut to keep food and liquids from flowing back up into the esophagus.

Detailed explanation-2: -Peristalsis is a series of wave-like muscle contractions that move food through the digestive tract. It starts in the esophagus where strong wave-like motions of the smooth muscle move balls of swallowed food to the stomach.

Detailed explanation-3: -Fortunately, there’s a band of muscle between the stomach and the esophagus-called the Lower Esophageal Sphincter or L-E-S, that clamps down to prevent the stomach contents from moving or refluxing upward and burning the lining of the esophagus.