| congenital giant pigmented nevus | These large pigmented (often hairy) congenital nevi are important because of their increased risk (10 to 15%) of conversion into malignant melanoma. A biopsy can confirm if cells have turned malignant. Any change in a pre-existing nevus should prompt a physician evaluation. (27 Sep 1997) |
|---|---|
| nevus, pigmented | A nevus containing melanin. The term is usually restricted to nevocytic nevi (round or oval collections of melanin-containing nevus cells occurring at the dermoepidermal junction of the skin or in the dermis proper) or moles, but may be applied to other pigmented nevi. (12 Dec 1998) |
| synovitis, pigmented villonodular | Outgrowths of synovial membrane composed of villi and fibrous nodules characterised histologically by haemosiderin- and lipid-containing macrophages and multinucleated giant cells. It usually occurs in the knee. (12 Dec 1998) |
| A layer | <molecular biology> Right handed double helical DNA with approximately 11 residues per turn. Planes of base pairs in the helix are tilted 20 deg away from perpendicular to the axis of the helix. Formed from B DNA by dehydration. (18 Nov 1997) |
| ameloblastic layer | The internal layer of the enamel organ. Synonym: enamel layer. (05 Mar 2000) |
| anterior elastic layer | 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) |
| anterior layer of rectus abdominis sheath | The portion of the rectus sheath that lies anterior to the muscle, consisting in its upper two-thirds of contributions from the aponeuroses of the external and internal oblique muscles, and in its lower third (below the arcuralt line) of contributions from the aponeuroses of all three muscles of the anterolateral abdominal wall. Synonym: lamina anterior vaginae musculi recti abdominis. (05 Mar 2000) |
| anterior limiting layer of cornea | 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) |
| bacillary layer | The layer of the retina next to the pigment layer and containing the visual receptors. See: retina, granular layers of retina, neuroepithelial layer of retina. Synonym: bacillary layer. (05 Mar 2000) |
| basal cell layer | The deepest layer of the epidermis, composed of dividing stem cells and anchoring cells. Synonym: basal cell layer, columnar layer, germinative layer, palisade layer, stratum basale, stratum cylindricum, stratum germinativum. (05 Mar 2000) |
| basal layer | The outermost layer of the endometrium which undergoes only minimal changes during the menstrual cycle. Synonym: basal layer. Synonym: stratum basale epidermidis. (05 Mar 2000) |
| basal layer of choroid | 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) |
| basal layer of ciliary body | The inner layer of the ciliary body, continuous with the basal layer of the choroid and supporting the pigment epithelium of the ciliary retina. Synonym: lamina basalis corporis ciliaris, basal layer of ciliary body. (05 Mar 2000) |
| boundary layer | <radiobiology> In fluid flow, a narrow region next to a fixed boundary or surface where the fluid velocity rapidly changes from zero to some finite value. The term has been generalised to situations with similar mathematics. (09 Oct 1997) |
| brown layer | An exceedingly delicate layer of loose, pigmented connective tissue on the inner surface of the sclera, connecting it with the choroid. Synonym: lamina fusca sclerae, brown layer, membrana fusca. (05 Mar 2000) |