| rubrospinal | Relating to the nerve fibres passing from the red nucleus to the spinal cord: the rubrospinal tract. (05 Mar 2000) |
|---|---|
| rubrospinal decussation | See: tegmental decussations. (05 Mar 2000) |
| rubrospinal tract | A somatotopically organised fibre bundle, relatively small in humans, arising from the red nucleus, immediately crossing in the ventral tegmental decussation, descending near the lateral surface of the brainstem into the lateral funiculus of the spinal cord at the ventral border of the lateral pyramidal tract. It terminates in the zona intermedia of the spinal cord where its distribution coincides with that of the lateral pyramidal tract; in contrast to the latter it appears not to have direct connections with spinal motor neurons. Impulses conveyed by this tract indirectly increase flexor muscle tone. Synonym: tractus rubrospinalis, Monakow's bundle, Monakow's tract, prepyramidal tract. (05 Mar 2000) |
| rubulavirus | A genus of the family paramyxoviridae (subfamily paramyxovirinae) where all the species have haemagglutinin and neuraminidase activities but lack a c protein. Mumps virus is the type species. (12 Dec 1998) |
| rubulavirus infections | Infections with viruses of the genus rubulavirus, family paramyxoviridae. (12 Dec 1998) |
| rubus | <botany> A genus of rosaceous plants, including the raspberry and blackberry. Origin: L. Source: Websters Dictionary (01 Mar 1998) |
| ruby | Origin: F. Rubis (cf. Pr. Robi), LL. Rubinus, robinus, fr. L. Rubeus = red, reddish, akin to ruber. See Rouge, red. 1. <chemical> A precious stone of a carmine red colour, sometimes verging to violet, or intermediate between carmine and hyacinth red. It is a red crystallized variety of corundum. Besides the true or Oriental ruby above defined, there are the balas ruby, or ruby spinel, a red variety of spinel, and the rock ruby, a red variety of garnet. "Of rubies, sapphires, and pearles white." (Chaucer) 2. The colour of a ruby; carmine red; a red tint. "The natural ruby of your cheeks." (Shak) 3. That which has the colour of the ruby, as red wine. Hence, a red blain or carbuncle. 4. See Agate. 5. <ornithology> Any species of South American humming birds of the genus Clytolaema. The males have a ruby-coloured throat or breast. <chemistry> Ruby of arsenic, Ruby of sulphur, red silver. See Red. Source: Websters Dictionary (01 Mar 1998) |
| ruby spots | <tumour> A red papule due to weakening of the capillary wall, seen mostly in persons over 30 years of age. Synonym: cherry angioma, De Morgan's spots, ruby spots. (05 Mar 2000) |
| rubytail | <zoology> A European gold wasp (Chrysis ignita) which has the under side of the abdomen bright red, and the other parts deep bluish green with a metallic luster. The larva is parasitic in the nests of other wasps and of bees. Source: Websters Dictionary (01 Mar 1998) |
| rubythroat | <ornithology> Any one of numerous species of humming birds belonging to Trochilus, Calypte, Stellula, and allies, in which the male has on the throat a brilliant patch of red feathers having metallic reflections; especially, the common humming bird of the Eastern United States (Trochilus colubris). Source: Websters Dictionary (01 Mar 1998) |
| rubywood | Red sandalwood. See Sandalwood. Source: Websters Dictionary (01 Mar 1998) |
| rucervine | <zoology> Of, like, or pertaining to, a deer of the genus Rucervus, which includes the swamp deer of India. Origin: NL. Rucervus, the genus, fr. NL. Rusa a certain genus of deer (Malay rsa deer) + Cervus. Source: Websters Dictionary (01 Mar 1998) |
| ruche | 1. A plaited, quilled, or goffered strip of lace, net, ribbon, or other material, used in place of collars or cuffs, and as a trimming for women's dresses and bonnets. Alternative forms: rouche. 2. A pile of arched tiles, used to catch and retain oyster spawn. Origin: F. Ruche ruche, beehive, OF. Rusche a beehive, which was formerly made of the bark of trees; cf. W. Rhisg, rhisgl, bark, gael. Rusg bark, rind. Source: Websters Dictionary (01 Mar 1998) |
| ructus | Synonym: eructation. Origin: L. Fr. Ructo, pp. -atus, to belch (05 Mar 2000) |
| rud | 1. Redness; blush. 2. Ruddle; red ocher. 3. <zoology> The rudd. Origin: AS. Rudu, akin to read red. See Red, and cf. Ruddy. Source: Websters Dictionary (01 Mar 1998) |