The esophagus, also known as the food pipe or gullet, is a muscular tube that plays a vital role in the digestive system. It is located in the throat and connects the mouth to the stomach. The esophagus is approximately 25 centimeters long and extends from the lower part of the pharynx to the upper part of the stomach.
The wall of the esophagus is composed of several layers. The innermost layer, known as the mucosa, is lined with moist and smooth tissue that allows food to pass through easily. It also contains glands that produce mucus to facilitate the movement of food.
Surrounding the mucosa is the submucosa, which contains blood vessels, nerves, and connective tissue. The muscular layer, known as the muscularis externa, consists of two types of muscles: circular muscles that contract to help propel food downward, and longitudinal muscles that aid in the peristaltic movement of food.
The outermost layer of the esophagus is the adventitia, which is made up of connective tissue that helps anchor the esophagus to surrounding structures.
The esophagus functions by transporting food from the mouth to the stomach through a series of coordinated muscle contractions called peristalsis. The upper esophageal sphincter at the top of the esophagus and the lower esophageal sphincter at the bottom of the esophagus help prevent food and stomach acid from refluxing back into the throat.