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Themoistened food bolus is moved to the back of the mouth by the tongue and pushedinto the pharynx. Here muscle contractions (circular muscle constrictions) takeplace and the swallowing reflex is triggered. Part of the swallowing actiontakes place as a reflex action, while part of it is under voluntary control.The food bolus is then pushed toward the esophagus, which is a muscular tubeextending from the esophagus. This swallowing reflex prevents the food fromentering in the wind pipe or trachea. Moreover, the flap-like epiglottis coversthe larynx, so that no food enters the trachea. The contraction of thelongitudinal muscles in the walls of the pharynx lifts the walls of the pharynxduring swallowing. When we swallow food, the food enters only the food pipe andnot the wind pipe. However, if we talk while eating, sometimes some foodparticles can enter the wind pipe and cause us to choke. The air inhaled fromthe nose and mouth is taken to the pharynx, from which it is sent to thetrachea or wind pipe. The air is then sent to the lungs. The mucus lining inthe walls of the or pharynx can change slightly to adapt both food as well asair, thus, the pharynx is also a part of the respiratory system. Any injury ordamage caused to the pharynx is seen to impede breathing. The process by whichhumans are able to make vocal sounds and speak is called vocalization. When airpasses through the pharynx and then into larynx, it causes the vocal cords inthe larynx to vibrate, thereby helping in production of sound, which is usedfor speech in humans. Eustachian tube or auditory tubes connect the middle earto the pharynx, at an opening in the nasopharyngeal region.

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  Thursday, August 3, 2017 at 6:06:37 AM

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