If the tube is obstructed because of inflammation of tubal tonsil, the remaining air in the middle ear is absorbed into the blood vessels of its mucous membrane, causing a fall of pressure in it and consequent retraction of tympanic membrane. The pharyngotympanic tube equalizes the pressure in the middle ear together with the atmospheric pressure to allow free movement of the tympanic membrane. An individual consumes once every minute when alert and once every 5 minutes when sleeping.The cilia of mucous lining of the tube beat in the course of nasopharynx and drain the secretion of the middle ear into the nasopharynx. Clearance of middle ear secretions by aggressive opening and closure of the tube.Protection of middle ear by preventing the transmission of high sound pressure from nasopharynx to middle ear as normally the tube stays closed. At rest, the tube stays closed but during swallowing, yawning and sneezing it reflexly opens. Preserves equilibrium of air pressure on each side of tympanic membrane.The following are the functions of the pharyngotympanic tube: Since the eustachian tube is shorter, wider and much more horizontal in babies, the infection from nasopharynx can easily get to the middle ear for this rationale, middle ear diseases are much more common in babies and young children than in adults. Oblique, directed downwards, forwards and medially (makes an angle of 45° with the horizontal plane) More or less horizontal (makes an angle of 10° with the horizontal plane) Pharyngotympanic Tubes of an Infant and an Adultĭifferences between the eustachian tube of an infant and an adult. The cilia beat in the course of nasopharynx and therefore help drain the secretions and fluid from the middle ear into the nasopharynx. The tube is lined by pseudostratified ciliated columnar epithelium with interspersed goblet cells. The pharyngeal orifice is the broadest part of the tube. It’s situated in the lateral wall of the pharynx, about 1.25 cm behind the posterior end of inferior nasal concha. The pharyngeal end is comparatively large and slit-like (vertically). It’s situated in the anterior wall of the middle ear, a little above its floor. The tympanic end of the tube is small and bony.
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