| germinal membrane | In many eggs with a large amount of yolk, cell division (cleavage) is restricted to a superficial layer of the fertilized egg (meroblastic cleavage). This layer is termed the blastoderm. In birds it is a flat disc of cells at one pole of the egg and in insects an outer layer of cells surrounding the yolk mass. (18 Nov 1997) |
|---|---|
| paroral membrane | <biology> In ciliates the cilia in the region of the mouth may be fused into a paroral membrane. (18 Nov 1997) |
| vestibular membrane | The membrane separating the cochlear duct from the vestibular canal; it consists of squamous epithelial cells with microvilli toward the ductus, a basement membrane, and a thin layer of connective tissue toward the scala. Synonym: membrana vestibularis, paries vestibularis ductus cochlearis, Reissner's membrane, vestibular wall of cochlear duct. (05 Mar 2000) |
| glassy membrane | The basement membrane present between the stratum granulosum and the theca interna of a vesicular ovarian follicle; it becomes very prominent in large atretic follicles, the basement membrane and associated connective tissue of the hair follicle. Synonym: hyaline membrane. (05 Mar 2000) |
| virginal membrane | An obsolete term for hymen. (05 Mar 2000) |
| reissner's membrane | <anatomy> The thin membrane which separates the canal of the cochlea from the vestibular scala in the internal ear. Origin: Named from E. Reissner, A German anatomist. Source: Websters Dictionary (01 Mar 1998) |
| Payr's membrane | A fold of peritoneum that crosses over the left flexure of the colon. (05 Mar 2000) |
| cell membrane | <cell biology> The structure enveloping a cell, enclosing the cytoplasm and forming a selective permeability barrier. It consists of lipids, proteins and some carbohydrates, the lipids thought to form a bilayer in which integral proteins are embedded to varying degrees. Synonym: plasma membrane. (26 Mar 1998) |
| cell membrane permeability | A quality of cell membranes which permits the passage of solvents and solutes into and out of cells. (12 Dec 1998) |
| vitelline membrane | <cell biology> The plasma membrane of the egg. (12 Dec 1998) |
| vitreous membrane | A condensation of fine collagen fibres in places in the cortex of the vitreous body; formerly thought to form a membrane or capsule at its periphery. Synonym: lamina basalis choroideae. See: posterior limiting layer of cornea (05 Mar 2000) |
| medullary membrane | <anatomy> The layer of vascular connective tissue lining the medullary cavities of bone. Origin: NL, fr. Gr. + a bone. Source: Websters Dictionary (01 Mar 1998) |
| pemphigoid, benign mucous membrane | A chronic blistering disease with predilection for mucous membranes and less frequently the skin, and with a tendency to scarring. It is sometimes called ocular pemphigoid because of conjunctival mucous membrane involvement. (12 Dec 1998) |
| reticular membrane | The membrane formed by cuticular plates of the cells of the spiral organ of Corti; it appears netlike when viewed from above. Synonym: membrana reticularis. (05 Mar 2000) |
| membrane | A thin layer of tissue which covers a surface, lines a cavity or divides a space or organ. (18 Nov 1997) |