swallowing

• oropharynx and laryngopharynx transmit food
• oropharynx communicates with nasopharynx superiorly and laryngopharynx inferiorly
• esophagus is the part of the digestive tract that extends between the pharynx and the stomach. It is about 25 cm long
• esophageal hiatus (opening)
• An upper esophageal sphincter and a lower esophageal sphincter, at the upper and lower ends of the esophagus, respectively, regulate the movement of materials into and out of the esophagus
• Swallowing, or deglutition, is divided into three phases: voluntary, pharyngeal, and esophageal
• voluntary phase, a bolus of food is formed in the mouth and pushed by the tongue against the hard palate
• pharyngeal phase of swallowing is a reflex initiated by the stimulation of tactile receptors in the area of the oropharynx.
• swallowing center in the medulla oblongata
• esophageal phase of swallowing, which takes about 5–8 seconds, is responsible for moving food from the pharynx to the stomach