Pars nasalis pharyngis

The upper portion of the pharynx, the nasopharynx, extends from the base of the skull to the upper surface of the soft palate.

It includes the space between the internal nares and the soft palate and lies above the oral cavity.

The adenoids, also known as the pharyngeal tonsils, are lymphoid tissue structures located in the posterior wall of the nasopharynx.

Waldeyer's tonsillar ring is an annular arrangement of lymphoid tissue in both the nasopharynx and oropharynx.

The nasopharynx is lined by respiratory epithelium that is pseudostratified, columnar, and ciliated.

Polyps or mucus can obstruct the nasopharynx, as can congestion due to an upper respiratory infection.

The auditory tube, which connects the middle ear to the pharynx, opens into the nasopharynx at the pharyngeal opening of the auditory tube.

The opening and closing of the auditory tubes serves to equalize the barometric pressure in the middle ear with that of the ambient atmosphere.

Details of torus tubarius

The anterior aspect of the nasopharynx communicates through the choanae with the nasal cavities.

On its lateral wall is the pharyngeal opening of the auditory tube, somewhat triangular in shape and bounded behind by a firm prominence, the torus tubarius or cushion, caused by the medial end of the cartilage of the tube that elevates the mucous membrane.

Two folds arise from the cartilaginous opening:

• the salpingopharyngeal fold, a vertical fold of mucous membrane extending from the inferior part of the torus and containing the salpingopharyngeus muscle