Simultaneously, the epiglottis (single cartilage at the upper part of the larynx) is pushed anteriorly to close the laryngeal inlet preventing food from entering the airways. Lastly, the laryngeal pharynx receives bolus from the oral pharynx and passes it into the esophagus for digestion.

These tubes are connected to the middle ears (tympanic cavities) posteriorly and mainly serve to equalize pressure and facilitate the drainage of the secretions of the middle ears. Second, the oral pharynx is a continuation of the oral cavity and functions to pass the bolus toward the laryngeal pharynx below.Īs the bolus passes from the oral cavity, the muscles of the soft palate contract to close the choanae so that food does not enter the nasal cavity. Also, within the lateral surface of the back of the nasopharynx, there are two openings, one on either side, which is called the auditory tubes (Eustachian tubes or pharyngotympanic tubes) surrounded by elevations of mucous membrane called tubal elevations. Regionally, the pharynx divides into three parts which are from superior to inferior:-the nasal pharynx, located behind the posterior nasal apertures (choanae), the oral pharynx, located behind the opening of the oral cavity, and the laryngeal pharynx, located behind the inlet (opening) of the larynx. First, the nasal pharynx is only related to the respiratory tract as air passes through it from the nasal cavities. Knowing its structure and function, embryology, neurovascular supply, musculature, surgical implications, and clinical significance will permit us to comprehend its importance. Its muscular-membranous integrity allows it to mediate several vital functions related to either organ system, e.g., food swallowing, air conduction, and voice production. It is funnel-shaped with its upper end being wider and located just below the lower surface of the skull, and its lower end is narrower and located at the level of the sixth cervical vertebra (C6) where the commencement of the esophagus posteriorly and the larynx anteriorly takes place. It is the main structure, in addition to the oral cavity, shared by two organ systems, i.e., the gastrointestinal tract (GIT) and the respiratory system. The inferior fibers are horizontal and continuous with the circular fibers of the esophagus the rest ascend, increasing in obliquity, and overlap the Constrictor medius.The pharynx is a conductive structure located in the midline of the neck. From these origins the fibers spread backward and medialward to be inserted with the muscle of the opposite side into the fibrous raphé in the posterior median line of the pharynx. On the thyroid cartilage it arises from the oblique line on the side of the lamina, from the surface behind this nearly as far as the posterior border and from the inferior cornu. From the cricoid cartilage it arises in the interval between the Cricothyreoideus in front, and the articular facet for the inferior cornu of the thyroid cartilage behind. The Inferior constrictor (Constrictor pharyngis inferior) the thickest of the three constrictors, arises from the sides of the cricoid and thyroid cartilage. Nerve: External laryngeal branch of thevagus

Inferior pharyngeal constrictor usmle