| Ramsay Hunt | See: Hunt. (05 Mar 2000) |
|---|---|
| Ramsay Hunt's syndrome | <syndrome> An intention tremor beginning in one extremity, gradually increasing in intensity, and subsequently involving other parts of the body. Synonym: progressive cerebellar tremor. Facial paralysis, otalgia, and herpes zoster resulting from viral infection of the seventh cranial nerve and geniculate ganglion, a form of juvenile paralysis agitans associated with primary atrophy of the pallidal system. Synonym: paleostriatal syndrome, pallidal syndrome. Synonym: Ramsay Hunt's syndrome. (05 Mar 2000) |
| Ramsden circle | <microscopy> The circular spot of light formed at that distance above the eyepiece where the chief image forming rays cross, the back focal plane of the eyepiece. The objective back focal plane is in conjugate focus in this same plane. In visual microscopy, the point where the pupil of the eye is placed. (05 Aug 1998) |
| Ramsden disk | <microscopy> The small circular patch of light that appears at the eyepoint above the ocular lens. This is the exit pupil of an optical instrument that, in a microscope adjusted for Koehler illumination, lies in a plane conjugate with the objective rear focal plane, condenser iris, and light source. Alteration of the Ramsden disk (for example, by the observer's iris) modifies the aperture function, diffraction pattern, and direction of view of the specimen. (05 Aug 1998) |
| Ramsden eyepiece | <microscopy> An ocular consisting of two plano-convex lenses with the plane side of the lower lens nearer the objective. The focal plane is outside the system, hence it is of the positive type with the diaphragm below the lenses. While this eyepiece gives a somewhat flatter field than the Huygenian and for this reason has been used in the past for micrometre oculars, the colour correction is poor with the formation of colour fringes around the object. The modern Ramsden eyepiece has an achromatic doublet for the eye lens to correct for colour. (05 Aug 1998) |
| Ramsden's ocular | An eyepiece of a microscope, consisting of two planoconvex lenses with convexities turned to each other. (05 Mar 2000) |
| Ramsden, Jesse | <person> English optician, 1735-1800. See: Ramsden's ocular. (05 Mar 2000) |
| ramson | <botany> A broad-leaved species of garlic (Allium ursinum), common in European gardens. Synonym: buckram. Origin: AS. Hramsan, pl, akin to G. Rams, Sw. Rams, ramslok; cf. Gr. Onion. Source: Websters Dictionary (01 Mar 1998) |
| ramsted | <botany> A yellow-flowered weed; so named from a Mr. Ramsted who introduced it into Pennsylvania. See Toad flax. Synonym: Ramsted weed. Source: Websters Dictionary (01 Mar 1998) |
| Ramstedt operation | Longitudinal incision through the anterior wall of the pyloric canal to the level of the submucosa, to treat hypertrophic pyloric stenosis. Synonym: Fredet-Ramstedt operation, Ramstedt operation. Origin: pyloro-+ G. Mys, muscle, + tome, incision (05 Mar 2000) |
| Ramstedt, Conrad | <person> German surgeon, 1867-1963. See: Ramstedt operation, Fredet-Ramstedt operation. (05 Mar 2000) |
| ramulus | <zoology> A small branch, or branchlet, of corals, hydroids, and similar organisms. Source: Websters Dictionary (01 Mar 1998) |
| ramus | A standard medical dictionary contains over 13 pages full of entries to the word ramus. Why? because ramus in latin means a branch and all sorts of anatomic items such as blood vessels and nerves quite naturally have branches. So, for example, medicine is plagued with the likes of the ramus acetabularis arteriae circumflexae femoris medialis which is simply the branch of an artery that goes to the acetabulum (the socket) of the hip joint. (12 Dec 1998) |
| ramus acetabularis | An arterial branch that supplies the acetabulum; two arteries, the obturator and the medial femoral circumflex, have such branches. Synonym: ramus acetabularis, acetabular artery, arteria acetabuli. (05 Mar 2000) |
| ramus acromialis arteriae suprascapularis | <anatomy, artery> Branch of suprascapular artery which pierces the origin of the trapezius muscle to run to the acromion; anastomoses, acromial branch of thoracoacromial artery. Synonym: ramus acromialis arteriae suprascapularis. (05 Mar 2000) |