abstract:The base of the cartilaginous portion of the eustachian tube (pharyngotympanic tube; auditory tube) lies directly under the mucous membrane of the nasal part of the pharynx, where it forms an elevation, the torus tubarius, the torus of the auditory tube, or cushion, behind the pharyngeal orifice of the tube. The torus tubarius is very close to the tubal tonsil,http://download.