The nasopharynx (the nasal part of the pharynx) is the uppermost part of the pharynx. It extends from the base of the skull to the upper surface of the soft palate. It differs from the oral and laryngeal parts of the pharynx in that its cavity always remains open in order to communicate with the choanae and the nasal cavity. On its lateral wall is the pharyngeal ostium of the auditory tube, which is somewhat triangular in shape and bounded in the back by a firm prominence, the torus tubarius or cushion, which is created by the medial end of the cartilage of the tube elevating the mucous membrane.
The nasopharynx is the most common place to harbor cold viruses. If further infected by bacteria, the nasopharynx is where physicians go to get a specimen for identification. Some of you may have experienced the nasal wash procedure: the doctor or nurse will inject several cc’s of normal saline into the deep part of your nasal passage and then withdraw the liquid. This liquid has millions of viruses or bacteria, or both, if you have an infection. This procedure provides a clue: the specimen has so many individual viruses or bacteria or both in a small volume, such as 5 cc’s. Now, think, if you ran more than 200 cc’s of liquid through the nasal and nasopharyngeal cavities, more viruses or bacteria would be cleaned out!