Gastrointestinal Anatomy And Physiology: The Es... 〈RELIABLE | 2027〉

The primary physiological function of the esophagus is deglutition, or swallowing. This is a complex process categorized into three phases:

The esophagus is approximately 25 centimeters long in adults. It is situated posterior to the trachea and heart, passing through the mediastinum of the thorax. It penetrates the diaphragm at an opening called the esophageal hiatus before connecting to the cardias of the stomach. Gastrointestinal Anatomy and Physiology: The Es...

As the peristaltic wave approaches the end of the esophagus, the LES relaxes. This relaxation is mediated by the vagus nerve and neurochemical transmitters like nitric oxide and vasoactive intestinal peptide. Once the food passes into the stomach, the LES constricts again to maintain a high-pressure barrier against gastric acid. Clinical Significance The primary physiological function of the esophagus is

This occurs when the LES fails to close adequately, allowing stomach acid to irritate the stratified squamous epithelium of the esophageal mucosa, causing heartburn. Chronic GERD can lead to Barrett's esophagus, where the normal squamous epithelium is replaced by columnar epithelium, increasing the risk of cancer. It penetrates the diaphragm at an opening called

This phase is also involuntary. Once the food enters the esophagus, a wave of coordinated muscular contractions called peristalsis begins. The circular muscles above the bolus contract to push it downward, while the longitudinal muscles below it shorten the tube. This wave propels the food toward the stomach regardless of gravity.