| pigmented retinal epithelium | Layer of unusual phagocytic epithelial cells lying below the photoreceptors of the vertebrate eye. The dorsal surface of the PRE cell is closely apposed to the ends of the rods and as discs are shed from the rod outer segment they are internalised and digested by the PRE. Do not have desmosomes or cytokeratins in some species. (18 Nov 1997) |
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| pigmented villonodular synovitis | <radiology> Monoarthritis, young adults, erosions on BOTH sides of joint (!), probably inflammatory, haemosiderin deposited in synovium, articular cartilage preserved (despite extensive marginal erosions; similar to gout), NO calcification Differential diagnosis: TB (associated atrophy of muscle and bone), rheumatoid arthritis (symmetrical), synovial sarcoma (with or without calcified; outside joint), synovial osteochondromatosis (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) |
| axillary hair | Hair of the armpit. (05 Mar 2000) |
| bamboo hair | Hair with regularly spaced nodules along the shaft caused by intermittent fractures with invagination of the distal hair into the proximal portion, with intervening lengths of normal hair, giving the appearance of bamboo; seen in Netherton's syndrome; autosomal recessive trait. Synonym: trichorrhexis invaginata. (05 Mar 2000) |
| bayonet hair | A spindle-shaped developmental defect occurring at the tapered end of the hair. (05 Mar 2000) |
| beaded hair | An autosomal dominant trichodystrophy in which brittle hairs show a series of constrictions, usually without a medulla. Synonym: beaded hair, moniliform hair. Origin: L. Monile, necklace, + G. Thrix, hair (05 Mar 2000) |
| bulb of hair | Hair bulb, the lower expanded extremity of the hair follicle that fits like a cap over the papilla pili. Synonym: bulbus pili, hair bulb. (05 Mar 2000) |
| maid's hair | <botany> The yellow bedstraw (Galium verum). Source: Websters Dictionary (01 Mar 1998) |
| vellus hair | Colourless, soft, fine postnatal to adult hair. (05 Mar 2000) |
| cartilage-hair hypoplasia | An autosomal recessive form of dwarfism characterised by shortness of the extremities without skull defects, and with sparse, brittle hair of light colour. There is a peculiar, not adequately explained severity in the clinical course of varicella and herpes in such patients. (05 Mar 2000) |
| vestibular hair cells | Cell's in the sensory epithelium of the maculae and cristae of the membranous labyrinth of the inner ear; afferent and efferent nerve fibres of the vestibular nerve end synaptically upon them; from the apical end of each cell a bundle of stereocilia and a kinocilium extend into the statoconial membrane of the maculae and the cupula of the cristae. (05 Mar 2000) |
| caterpillar-hair ophthalmia | The presence of nodular swellings on the conjunctiva, due to penetration of ocular tissues by the hairs of caterpillars. Synonym: caterpillar-hair ophthalmia. (05 Mar 2000) |
| medulla of hair shaft | The central axis of some hairs, containing a column of large vacuolated and keratinised cells; the medullary portion is surrounded by the cortex. (05 Mar 2000) |
| menkes kinky-hair syndrome | <radiology> Defective intestinal copper absorption, X-linked recessive, males only, presents in early infancy, Wormian bones (12 Dec 1998) |