| tympanic plate of temporal bone | The bony plate forming the greater part of the anterior wall of the bony part of the external acoustic meatus and the tympanic cavity and the posterior wall of the mandibular fossa. Synonym: pars tympanica ossis temporalis, tympanic part of temporal bone. (05 Mar 2000) |
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| tympanic plexus | A plexus on the promontory of the labyrinthine wall of the tympanic cavity, formed by the tympanic nerve, an anastomotic branch of the facial, and sympathetic branches from the internal carotid plexus; it supplies the mucosa of the middle ear, mastoid cells, and auditory (eustachian) tube, and gives off the lesser superficial petrosal nerve to the otic ganglion. Synonym: plexus tympanicus, Jacobson's plexus. (05 Mar 2000) |
| tympanic promontory | A rounded eminence on the labyrinthine wall of the middle ear, caused by the first coil of the cochlea. Synonym: promontorium cavi tympani, tuber cochleae, tympanic promontory. (05 Mar 2000) |
| tympanic ring | In the foetus, a more or less complete bony ring at the medial end of the cartilaginous external acoustic meatus, to which is attached the tympanic membrane. Synonym: annulus tympanicus, tympanic bone. (05 Mar 2000) |
| tympanic sinus | A depression in the tympanic cavity posterior to the tympanic promontory. Synonym: sinus tympani. Sinus unguis, the deep cleft housing the root of the nail. Synonym: sinus of nail. (05 Mar 2000) |
| tympanic veins | Veins exiting from the tympanic cavity through the petrotympanic fissure with the chorda tympani and emptying into the retromandibular vein. Synonym: venae tympanicae. (05 Mar 2000) |
| tympanic wall of cochlear duct | The wall that separates the cochlear duct from the scala tympani; it consists of the osseous spiral lamina and the basilar membrane. Synonym: paries tympanicus ductus cochlearis, membrana spiralis, spiral membrane. (05 Mar 2000) |
| umbo of tympanic membrane | The projection on the inner surface of the tympanic membrane at the end of the manubrium of the malleus; this corresponds to the most depressed point of the membrane, viewed laterally, that is commonly called the umbo. Synonym: umbo membranae tympani, umbo. (05 Mar 2000) |
| flaccid part of tympanic membrane | Triangular loose part of tympanic membrane between the malleolar folds. Synonym: pars flaccida membranae tympani, flaccid membrane, membrana flaccida, Rivinus' membrane, Shrapnell's membrane. (05 Mar 2000) |
| floor of tympanic cavity | The floor of the tympanic cavity; a thin plate of bone separating the tympanic cavity from the jugular fossa. Synonym: paries jugularis cavi tympani, fundus tympani, inferior wall of tympanic cavity, jugular wall of middle ear. (05 Mar 2000) |
| lateral wall of tympanic cavity | The wall formed mainly by the tympanic membrane. Synonym: paries membranaceus cavi tympani, lateral wall of middle ear, membranous wall of middle ear. (05 Mar 2000) |
| lesser tympanic spine | The posterior edge of the tympanic notch (of Rivinus). Synonym: spina tympanica minor. (05 Mar 2000) |
| limbus of tympanic membrane | Margin of the tympanic membrane attaching to the tympanic sulcus. Synonym: limbus membranae tympani. (05 Mar 2000) |
| abducens nerve | <anatomy, nerve> The 6th cranial nerve. The abducens nerve originates in the abducens nucleus of the pons and sends motor fibres to the lateral rectus muscles of the eye. Damage to the nerve or its nucleus disrupts horizontal eye movement control. (12 Dec 1998) |
| abducent nerve | <anatomy> The abducent nerve enervates a muscle which moves the eyeball. Lesions of the sixth cranial nerve result in deviation of the eyeball outward and double vision. Synonym: cranial nerve VI. (27 Sep 1997) |