| basilar membrane | A thin layer of tissue covered with mesothelial cells that separates the cochlea from the scala tympani in the ear. (18 Nov 1997) |
|---|---|
| basolateral plasma membrane | <cell biology> The plasma membrane of epithelial cells that is adjacent to the basal lamina or the adjoining cells of the sheet. Differs both in protein and phospholipid composition from the apical plasma membrane from which it is isolated by tight junctions (zonula occludentes). (18 Nov 1997) |
| Bichat's membrane | The inner elastic membrane of arteries. (05 Mar 2000) |
| black membrane | <chemistry> An artificial phospholipid membrane formed by painting a solution of phospholipid in organic solvent over a hole in a hydrophobic support immersed in water. Drainage of the solvent from the film produces diffraction colours until the thickness falls below the wavelength of light it then appears to be black. The structure is an extended bimolecular leaflet. (18 Nov 1997) |
| Bogros' serous membrane | A membrane of the episcleral space (of Tenon). (05 Mar 2000) |
| Bowman's membrane | A transparent homogeneous acellular layer, 6 to 9 um thick, lying between the basal lamina of the outer layer of stratified epithelium and the substantia propria of the cornea; considered to be a basement membrane. Synonym: lamina limitans anterior corneae, anterior elastic layer, Bowman's membrane, lamina elastica anterior, limiting layers of cornea. (05 Mar 2000) |
| branch of auriculotemporal nerve to tympanic membrane | Sensory branch of the auriculotemporal nerve supplying the external surface of the tympanic membrane. Synonym: ramus membranae tympani nervi auriculotemporalis, nerve of tympanic membrane. (05 Mar 2000) |
| bruch membrane | The membrane, also called the lamina basalis choroideae, that acts as a support structure on the inner side of the choroid (the vascular sheet that supplies the retinal pigment epithelium and the outer portion of the sensory retina adjacent to it). It is 7 microns thick and is composed of the basement membranes of the choriocapillaris endothelium and the retinal pigment epithelium. The membrane stops at the optic nerve, as does the retinal pigment epithelium. (12 Dec 1998) |
| Bruch's membrane | The transparent, nearly structureless inner layer of the choroid in contact with the pigmented layer of the retina. Synonym: basal lamina of choroid, basal layer of choroid, Bruch's membrane, Henle's membrane, lamina vitrea, vitreous lamella, vitreous membrane. (05 Mar 2000) |
| Brunn's membrane | The epithelium of the olfactory region of the nose. (05 Mar 2000) |
| bucconasal membrane | A thin, transient epithelial sheet separating the primitive nasal cavity from the stomodeum in the seven-week-old human embryo. Synonym: oronasal membrane. (05 Mar 2000) |
| buccopharyngeal membrane | A bilaminar (ectoderm and endoderm) membrane derived from the prochordal plate; after the embryonic head fold has evolved it lies at the caudal limit of the stomodeum. Synonym: oral membrane, oropharyngeal membrane. (05 Mar 2000) |
| vaginal synovial membrane | A sheath of synovial membrane enveloping certain of the tendons; it contains a small amount of synovial fluid. Synonym: vagina synovialis tendinis, mucous sheath of tendon, theca tendinis, vagina mucosa tendinis, vaginal synovial membrane. (05 Mar 2000) |
| radiate layer of tympanic membrane | The connective tissue layer of the tympanic membrane beneath the stratum cutaneum, the fibres of which radiate from the manubrium of the malleus to the peripheral fibrocartilaginous ring of the membrane; absent from the pars flaccida. Synonym: radiate layer of tympanic membrane. (05 Mar 2000) |
| 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) |