Pharynx

PHARYNX

As described in the preceding, the oropharynx and laryngopharynx are food passageways connecting the oral cavity to the esophagus. No digestion takes place in the pharynx. Its only related function is swal-lowing, the mechanical movement of food. When the bolus of food is pushed backward by the tongue, the constrictor muscles of the pharynx contract as part of the swallowing reflex. The reflex center for swallow-ing is in the medulla, which coordinates the many actions that take place: constriction of the pharynx, cessation of breathing, elevation of the soft palate to block the nasopharynx, elevation of the larynx and clo sure of the epiglottis, and peristalsis of the esophagus. As you can see, swallowing is rather complicated, but because it is a reflex we don’t have to think about mak-ing it happen correctly. Talking or laughing while eat-ing, however, may interfere with the reflex and cause food to go into the “wrong pipe,” the larynx. When that happens, the cough reflex is usually effective in clearing the airway.