| structural colour | A colour created by an optical effect (e.g., via interference, refraction, or diffraction). Many naturally occurring blues fall in this class. Compare: natural pigment. Synonym: schemochromes. (05 Mar 2000) |
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| Doppler colour flow | A computer-generated colour image produced by Doppler ultrasonography in which different directions of flow are represented by different hues. This technique is typically used to examine blood flow when evaluating heart disease. Where obstructions (for instance, arterial plaques) exist, blood flow will alter according to the principles of fluid mechanics. Eddies and reversals are readily apparent on the colour image. See: Doppler ultrasonography. (05 Mar 2000) |
| incidental colour | An obsolete term for a colour impression that remains after removal of the source. See: afterimage. (05 Mar 2000) |
| intrinsic colour | <dentistry> The addition of colour pigment within the material of a dental prosthesis. (05 Mar 2000) |
| opponent colour | Pairs of colour that share colour channels in the retina (red-green, blue-yellow, black-white). (05 Mar 2000) |
| echocardiography, doppler, colour | Echocardiography applying the doppler effect, with the superposition of flow information as colours on a gray scale in a real-time image. (12 Dec 1998) |
| tone colour | The distinguishing quality of a sound, by which one may determine its source. Synonym: tone colour. Origin: Fr. (05 Mar 2000) |
| extrinsic colour | Colour applied to the external surface of a dental prosthesis. (05 Mar 2000) |
| eye colour | Colour of the iris. (12 Dec 1998) |
| Young-Helmholtz theory of colour vision | A theory that there are three colour-perceiving elements in the retina: red, green, and blue. Perception of other colours arises from the combined stimulation of these elements; deficiency or absence of any one of these elements results in inability to perceive that colour and a misperception of any other colour of which it forms a part. Synonym: Helmholtz theory of colour vision. (05 Mar 2000) |
| ultrasonography, doppler, colour | Ultrasonography applying the doppler effect, with the superposition of flow information as colours on a gray scale in a real-time image. This type of ultrasonography is well-suited to identifying the location of high-velocity flow (such as in a stenosis) or of mapping the extent of flow in a certain region. (12 Dec 1998) |
| Farnsworth-Munsell colour test | A test for colour perception; the task is to arrange 84 colour disks (in four separate racks of 20-22 disks) in a sequence with minimal separation of hue between adjacent disks. (05 Mar 2000) |
| anterior white commissure | A narrow band of white substance bordering on the anterior median fissure of the spinal cord in front of the anterior gray commissure, and consisting of nerve fibres crossing over from one half of the spinal cord to the other. Synonym: commissura alba, anterior white commissure, commissura ventralis alba, ventral white column. (05 Mar 2000) |
| Bouffardi's white mycetoma | <dermatology> A form of mycetoma common in India and found occasionally in Somalia, caused by the organism Streptomyces somaliensis; in this variety, the muscles, tendons, and bones of the foot are destroyed by the disease process; numerous draining sinuses discharge yellowish grains, clustered like fish roe. (05 Mar 2000) |
| Brumpt's white mycetoma | Mycetoma caused by Pseudallescheria boydii, occurring in temperate and subtropical areas in India; small, white to yellow, hard to soft granules are discharged through the draining sinuses. (05 Mar 2000) |