| yellow spot | An oval area of the sensory retina, 3 by 5 mm, temporal to the optic disk corresponding to the posterior pole of the eye; at its centre is the central fovea, which contains only retinal cones. Synonym: area centralis, macula lutea, macular area, punctum luteum, Soemmerring's spot, yellow spot. (05 Mar 2000) |
|---|---|
| yellow vision | <ophthalmology> A form of chromatopsia in which objects looked at appear yellow. Origin: Gr. Opsis = vision (11 May 1997) |
| yellow wax | A yellowish, solid, brittle substance prepared from the honeycomb of the bee, Apis mellifera; the chief constituent is myricin (myricyl palmitate); others are cerotic acid (cerin), melissic acid, heptacosane, and hentriacontane; used in the preparation of ointments, cerates, plasters, and suppositories. (05 Mar 2000) |
| yellow yolk | The chief constituent of the yolk in a bird's egg; it consists of relatively coarse particles of stored food materials and is laid down in concentric zones with interposed thin layers of white yolk. (05 Mar 2000) |
| Leipzig yellow | A fine yellow powder used in paints and dyes. Synonym: lead chromate, Leipzig yellow, lemon yellow, Paris yellow. (05 Mar 2000) |
| lemon yellow | A fine yellow powder used in paints and dyes. Synonym: lead chromate, Leipzig yellow, lemon yellow, Paris yellow. (05 Mar 2000) |
| alum root | <botany> A North American herb (Heuchera Americana) of the Saxifrage family, whose root has astringent properties. Source: Websters Dictionary (01 Mar 1998) |
| anatomical root | That portion of a tooth extending from the cervical line to its apical extremity. (05 Mar 2000) |
| angelica root | The root of Angelica archangelica (family Umbelliferae); a tonic and stimulant that may cause nausea; used as a carminative, diuretic, and externally as a counterirritant. (05 Mar 2000) |
| anterior root | The motor root of a spinal nerve. Synonym: radix anterior, radix motoria, anterior root, motor root, radix ventralis. (05 Mar 2000) |
| aquatic root | <plant biology> Roots that develop on stems above the normal position occupied by roots, in response to prolonged inundation with water. (09 Oct 1997) |
| arched root | <botany> Roots produced on the plant stems in a position above the normal position of roots, which serve to brace the plant during and following periods of prolonged inundation with water. (09 Oct 1997) |
| black root | <botany> Dried rhizome and roots of Veronicastrum virginicum (family Serophulariaceae). Indigenous to North America. Formerly used as a cathartic. Synonym: black root, Culver's root. (05 Mar 2000) |
| vandal root | <botany> Any plant of the genus Valeriana. The root of the officinal valerian (V. Officinalis) has a strong smell, and is much used in medicine as an antispasmodic. <botany> Greek valerian, a plant (Polemonium caeruleum) with blue or white flowers, and leaves resembling those of the officinal valerian. Origin: LL. Valeriana, perhaps from some person named Valerius, or fr. L. Valere to be strong. Powerful, on account of its medicinal virtues: cf. F. Valeriane. Source: Websters Dictionary (01 Mar 1998) |
| ganglion cells of dorsal spinal root | Pseudounipolar nerve cell bodies in the ganglia of the dorsal spinal nerve roots; the sensory spinal nerves are composed of the peripheral axon branches of these sensory ganglion cell's, whereas the central axon branch of each such cell enters the spinal cord as a component of the dorsal root. (05 Mar 2000) |