• Location: superior to soft palate and posterior to the two choanae of the nasal cavity, anterior to occipital bone. Contains adenoid tissue and the orifices of the eustachian tubes.

• Lateral and posterior walls are formed by the mucosa lining the inside of the upper part of the superior constrictor muscle and the 2 palatal muscles surrounding the opening of the auditory tube (levator palati and tensor palati). Nasopharynx remains open even when muscles contract to insure patency of respiratory airway.
• Posteriorly, opening of the Eustachian (auditory) tube surrounded by the salpingopharyngeal fold and the tubular tonsil (which may enlarge during an infection).

• Salpingopharyngeal fold: Vertical fold of mucous membrane extending medially from the eustachian tube which surrounds the salpingopharyngeus muscle which opens the pharyngeal orifice of the pharyngotympanic tube during swallowing
• Tubular Tonsils: Lymphoid tissue in the submucosa of the pharynx near the pharyngeal orafice of the eustachian tube

• Pharyngeal recess: a slitlike lateral projection posterior to torus tubarous and the salpingopharyngeal fold
• Contents - 1) pharyngeal tonsil (lymphoid tissue in submucosa of roof and posterior wall of nasopharynx); 2) opening of auditory tube
• Nasopharyngeal tonsils are located on the posterior and superior walls of the pharynx. The abundant lymphoid tissue forms an incomplete tonsillar ring about the superior part of the pharynx – Waldeyer’s Ring. When they become enlarged, they are called adenoids and may turn the individual into a mouth-breather. Adenoidectomy is indicated.

• Clinical: Adenoids- enlargement of pharyngeal tonsil common in children; can interfere with breathing and can cause a blocking of the Eustachian tubes which may result in otitis media

***Soft palate separates the nasopharynx from the oropharynx***

• Location - Superior boundary: soft palate; inferior boundary: upper border of epiglottis (vallecula fossa) and root of the tongue; located posterior to palatoglossal arch

• Posterior and lateral walls are formed by the superior and middle pharyngeal constrictors and Gap #2.
• Embryology Note: continuous with the oral cavity anteriorly, it is demarcated by the palatoglossal arches (embryonic buccopharyngeal membrane) separating the ectodermal stomodeum from the endodermal foregut.

• The Palatine Tonsils deserve special mention here - lymphoid aggregates between the mucosal folds created by the palatoglossus and palatopharyngeus muscles located in the oropharynx inferior to the soft palate (tonsillar fossa)

• Palatine tonsil is contained in the triangular area between the 2 above muscles (pillars of the fauces), called the fauces.
• Palatoglossus m., underlying the palatoglossal folds is a depressor of the soft palate and is innervated by X. It lies anterior to the palatine tonsil, attaching to the side of the tongue at the junction between its anterior 2/3 and posterior 1/3.
• Palatopharyngeus m. lies posterior to the palatine tonsil. It elevates the larynx during swallowing and depresses the soft palate during respiration. It is innervated by X.
• They are covered by stratified squamous epithelium, which continues down into deep crypts.
• Tonsils vary widely in size and may be sessile or pedunculated.
• Vascularization

• Palatine tonsil is vascularized by the tonsillar branches of the ascending pharyngeal and facial arteries.
• The lingual artery may also provide tonsillar branches of the Greater Palatine a.
• This extensive vascularization is important to consider during a tonsillectomy where the tonsils may bleed extensively.

• The mucosa over the tonsils is innervated by sensory branches of IX; stimulation provokes the gag reflex (this is a good way to test sensory IX).

• Location - between upper border of epiglottis superiorly and lower border of cricoid cartilage inferiorly (C6); communicates inferiorly with esophagus and anteriorly with larynx; bounded anteriorly by the epiglottis, and posteriorly by the mucosa and muscles attaching to the arytenoid cartilages.
• The opening of the larynx is obliquely oriented.
• The lateral walls of the pharynx here form the aryepiglottic folds.

• During swallowing, elevation of the larynx, contraction of the aryepiglottic folds and posteroinferior tilting of the epiglottis closes the inlet to the larynx and direct food and drink lateral to aryepiglottic folds and into the piriform fossa.
• During breathing, the larynx descends and the tongue protrudes forward.

• Between the anterior surface of the epiglottis and the posterior surface of the tongue are the vallecular fossae separated by a glossoepiglottic fold.

• The vallecular fossae communicate with the piriform recesses lateral to the aryepiglottic folds.

• This is the territory of the internal laryngeal nerve (X)

• sensory for the cough reflex
• innervates the mucosa lining interior of larynx, superior to the vocal cords (also area for cough reflex).