MEDICAL PHYSIOLOGY

Detailed explanation-1: -Just before entering the stomach, the esophagus passes through the diaphragm. The upper esophageal sphincter (UES) is a bundle of muscles at the top of the esophagus.

Detailed explanation-2: -Upper and lower esophageal sphincters control the movement of food into and out of the esophagus. The lower esophageal sphincter is sometimes called the cardiac sphincter and resides at the esophagogastric junction.

Detailed explanation-3: -Because of the two structures it joins, the lower esophageal sphincter is also known as the gastroesophageal sphincter or gastroesophageal junction. Because of its closeness to the heart, it is also known as the cardiac sphincter.