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Halipegus eccentricus is a monoecious, digenea parasitic trematode commonly found in true frogs in North America.It was first described in 1939. [1]H. eccentricus is mainly found in the Eustachian tubes of a variety of frog species, its definitive host, although its life cycle involves other hosts, as is common for trematodes.
All native New Zealand frogs (pepeketua in Māori) share tail-wagging muscles, inscriptional ribs, round pupils, and a lack of eardrums, eustachian tubes, and vocal sacs. These frogs, in some ways more similar to salamanders than modern frogs, use chemical signals over acoustic signals to mark habitat and recognize competitors. [8]
The Eustachian tube (/ j uː ˈ s t eɪ ʃ ən /), also called the auditory tube or pharyngotympanic tube, [1] 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 35 mm (1.4 in) long and 3 mm (0.12 in) in diameter. [ 2 ]
The middle ear is the portion of the ear medial to the eardrum, and distal to the oval window of the cochlea (of the inner ear).. The mammalian middle ear contains three ossicles (malleus, incus, and stapes), which transfer the vibrations of the eardrum into waves in the fluid and membranes of the inner ear.
The middle ear also connects to the upper throat at the nasopharynx via the pharyngeal opening of the Eustachian tube. [3] [11] The three ossicles transmit sound from the outer ear to the inner ear. The malleus receives vibrations from sound pressure on the eardrum, where it is connected at its longest part (the manubrium or handle) by a ligament.
The endoderm lines the future auditory tube (pharyngotympanic Eustachian tube), middle ear, mastoid antrum, and inner layer of the tympanic membrane. Derivatives of this pouch are supplied by Mandibular nerve.
A tympanostomy tube is inserted into the eardrum to keep the middle ear aerated for a prolonged time and to prevent reaccumulation of fluid. Without the insertion of a tube, the incision usually heals spontaneously in two to three weeks. Depending on the type, the tube is either naturally extruded in 6 to 12 months or removed during a minor ...
The torus tubarius (or torus of the auditory tube) is an elevation of the mucous membrane of the nasal part of the pharynx formed by the underlying base of the cartilaginous portion of the Eustachian tube (auditory tube). The torus tubarius is situated behind the pharyngeal orifice of the auditory tube. [1]