The base of the cartilaginous portion of the auditory tube (eustachian tube, pharyngotympanic 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, which is sometimes also called the tonsil of (the) torus tubarius. Equating the torus with its tonsil however might be seen as incorrect or imprecise. The base of the cartilaginous portion of the auditory tube (eustachian tube, pharyngotympanic 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, which is sometimes also called the tonsil of (the) torus tubarius. Equating the torus with its tonsil however might be seen as incorrect or imprecise.