Upper Digestive Tract
3D visualization reconstructed from scanned human data of the structures involved in the action of swallowing. A bolus of food is depicted in the esophagus. The epiglottis bent down to cover the windpipe to allow for the passage of the bolus. Swallowing, or deglutition, is a complicated process involving over 22 muscle groups and the coordination of the tongue, soft palate, pharynx, and esophagus. The first stage is voluntary, when the tongue is pressed against the roof of the mouth and is contracted to pass the food to the oropharynx. The second stage ,which is involuntary, involves the uplifting of the larynx to allow the epiglottis to cover the trachea while peristaltic contractions moves food down the pharynx and esophagus.