| tense part of the tympanic membrane | The greater portion of the tympanic membrane which is tense and firm, contrasting with the small triangular flaccid part of tympanic membrane. Synonym: pars tensa membranae tympani, membrana tensa, membrana vibrans. (05 Mar 2000) |
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| tensor muscle of tympanic membrane | <anatomy, muscle> Origin, the cartilaginous part of the auditory (eustachian) tube and the walls of its hemi-canal just above the bony portion of the auditory tube; insertion, handle of malleus; action, draws the handle of the malleus medialward tensing the tympanic membrane to protect it from excessive vibration by loud sounds. Nerve supply, branches of trigeminal through the otic ganglion. Synonym: musculus tensor tympani, tensor muscle of tympanic membrane, Toynbee's muscle. (05 Mar 2000) |
| tertiary egg membrane | See: egg membrane. (05 Mar 2000) |
| thyrohyoid membrane | A thin, fibrous, membranous sheet filling the gap between the hyoid bone and the thyroid cartilage. Synonym: membrana thyrohyoidea, membrana hyothyroidea. (05 Mar 2000) |
| egg membrane | The investing envelope of the ovum; a primary egg membrane is produced from ovarian cytoplasm (e.g., a vitelline membrane); a secondary egg membrane is the product of the ovarian follicle (e.g., the zona pellucida); a tertiary egg membrane is secreted by the lining of the oviduct (e.g., a shell). (05 Mar 2000) |
| elastic membrane | A membrane formed of elastic connective tissue, present as fenestrated lamellae in the coats of the arteries and elsewhere. (05 Mar 2000) |
| Toldt's membrane | The anterior layer of the renal fascia. (05 Mar 2000) |
| embryonic membrane | A structure or tissue that develops from the fertilised ovum but does not form part of the embryo proper. Synonym: embryonic membrane, extraembryonic membrane. (05 Mar 2000) |
| Tourtual's membrane | The elastic fibra membrane that extends from the ventricular fold of the larynx upward to the aryepiglottic fold; it attaches anteriorly to the epiglottis and posteriorly to the lateral margin of the arytenoid and corniculate cartilages. Synonym: membrana quadrangularis, Tourtual's membrane. (05 Mar 2000) |
| enamel membrane | The internal layer of the enamel organ formed by the enamel cells. (05 Mar 2000) |
| epipapillary membrane | A congenital membrane covering the optic disk, the glial remnants of Bergmeister's papilla. (05 Mar 2000) |
| epiretinal membrane | A membrane on the vitreal surface of the retina resulting from the proliferation of one or more of three retinal elements: (1) fibrous astrocytes; (2) fibrocytes; and (3) retinal pigment epithelial cells. Localised epiretinal membranes may occur at the posterior pole of the eye without clinical signs or may cause marked loss of vision as a result of covering, distorting, or detaching the fovea centralis. Epiretinal membranes may cause vascular leakage and secondary retinal oedema. In younger individuals some membranes appear to be developmental in origin and occur in otherwise normal eyes. The majority occur in association with retinal holes, ocular concussions, retinal inflammation, or after ocular surgery. (12 Dec 1998) |
| Epithelial membrane antigen | <cell biology> Heavily glycosylated membrane glycoprotein. Encoded by the MUC 1 gene, has a molecular weight of around 300 kD, more than half of which is O linked glycan. There is a 69 residue cytoplasmic domain and the extracellular domain may extend hundreds of nanometres beyond the plasma membrane, the increased expression in carcinoma cells may reduce the adhesion and mask antigenic properties of the cells. Similar functions are ascribed to ASGP, epiglycanin and leucosialin. (18 Nov 1997) |
| erythrocyte membrane | The semipermeable outer portion of the red corpuscle. It is known as a 'ghost' after haemolysis. (12 Dec 1998) |
| Jackson's membrane | A thin vascular membrane or veil-like adhesion, covering the anterior surface of the ascending colon from the caecum to the right flexure; it may cause obstruction by kinking of the bowel. Synonym: Jackson's veil. (05 Mar 2000) |