Esophagus

Monday, January 12, 2009

The esophagus is an organ that is part of the digestive tract and consists of a muscular tube through which food passes from the pharynx to the stomach. In humans the esophagus is continuous with the laryngeal part of the pharynx at the level of the C6 vertebra. The esophagus passes through a hole in the thoracic diaphragm called the esophageal hiatus. It is usually 25-30 cm long and is divided into three parts; the cervical, thoracic, and abdominal parts.

Food is pushed down the esophagus through a process called peristalsis. The esophagus is deeply lined with muscle that acts with peristaltic action to move swallowed food down to the stomach. Due to the fact that the esophagus lacks the mucus lining like that of the stomach, it can get irritated by stomach acid that passes the cardiac sphincter, which is the junction between the esophagus and the stomach.