The base of the

cartilaginous Cartilage is a resilient and smooth type of connective tissue. In tetrapods, it covers and protects the ends of long bones at the joints as articular cartilage, and is a structural component of many body parts including the rib cage, the neck a ...

portion of the

Eustachian tube In anatomy, the Eustachian tube, also known as the auditory tube or pharyngotympanic tube, is a tube that links the nasopharynx to the middle ear, of which it is also a part. In adult humans, the Eustachian tube is approximately long and in d ...

(auditory tube) lies directly under the

mucous membrane A mucous membrane or mucosa is a membrane that lines various cavities in the body of an organism and covers the surface of internal organs. It consists of one or more layers of epithelial cells overlying a layer of loose connective tissue. It i ...

of the

nasal part of the pharynx The pharynx (plural: pharynges) is the part of the throat behind the mouth and nasal cavity, and above the oesophagus and trachea (the tubes going down to the stomach and the lungs). It is found in vertebrates and invertebrates, though its s ...

, where it forms an elevation or cushion, the torus tubarius or torus of the auditory tube, behind the pharyngeal orifice of the tube. The torus tubarius is very close to the

tubal tonsil The tubal tonsil, also known as Gerlach tonsil, is one of the four main tonsil groups forming Waldeyer's tonsillar ring. Structure Each tubal tonsil is located posterior to the opening of the Eustachian tube on the lateral wall of the naso ...

, which is sometimes also called the ''tonsil of (the) torus tubarius''. Two folds run posteriorly and anteriorly: *posteriorly, the vertical fold of mucous membrane, the salpingopharyngeal fold, stretches from the lower part of the torus tubarius; it contains the

Salpingopharyngeus muscle The salpingopharyngeus muscle is a muscle of the pharynx. It arises from cartilage around the Eustachian tube, and inserts into the palatopharyngeus muscle by blending with its posterior fasciculus. It raises the pharynx and larynx during deg ...

which originates from the superior border of the medial lamina of the cartilage of the auditory tube,FUNCTIONAL ANATOMY OF THE EUSTACHIAN TUBE. CLEVELAND S. SIMKINS, PH.D. Arch Otolaryngol. 1943;38(5):476-484.
/ref> and passes downward and blends with the posterior fasciculus of the

palatopharyngeus muscle The palatopharyngeus (palatopharyngeal or pharyngopalatinus) muscle is a small muscle in the roof of the mouth. It is a long, fleshy fasciculus, narrower in the middle than at either end, forming, with the mucous membrane covering its surface, the ...

. *anteriorly, the second and smaller fold, the salpingopalatine fold, smaller than the salpingopharyngeal fold, contains some fibers of muscle, called ''salpingopalatine muscle'' by Simkins (1943), it stretches from the superior border of lateral lamina of the cartilage, anteroinferiorly, to the back of the hard palate. The

tensor veli palatini The tensor veli palatini muscle (tensor palati or tensor muscle of the velum palatinum) is a broad, thin, ribbon-like muscle in the head that tenses the soft palate. Structure The tensor veli palatini is found anterior-lateral to the levator ve ...

does not contribute to the fold, since the origin is deep to the cartilaginous opening.

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* * * {{Authority control Ear

See also

References

External links