Virtual Chicken: The Esophagus

The esophagus of a chicken is a thin-walled, expansive tube that transports food from the mouth of the pharynx to the stomach. As food moves towards the back of the tongue, the choana reflexively closes. In the pharyngeal phase, the infundibular mound and glottis close, the tongue is moved backward, and the esophagus is moved forward, decreasing the distance between the oral cavity and the esophagus. The avian esophagus allows birds to swallow their food whole. Its walls are made up of four layers: mucosal, submucosal, muscle tunic, and the serosal layer, which contains only smooth muscle cells. In addition, the esophagus is divided into two sections: the cervical, near the beak, and thoracic region, near the crop. The esophagus is lined with epithelium tissue which contains mucous glands. These glands are more numerous in the thoracic esophagus while being absent in the cervical region. Food is moved through the esophagus via the excitement of the myenteric plexus nerve rather than the muscles. For More In