| false projection | <ophthalmology> The faulty visual sensation arising secondarily to underaction of an ocular muscle. Synonym: erroneous projection. (05 Mar 2000) |
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| Fischer projection formula | <biochemistry> Of sugars, representations, by projection, of cyclic sugars, or derivatives thereof, in which the carbon chain is depicted vertically. The lowest-numbered asymmetric carbon atom (C-1 in aldoses; C-2 in 2-ketoses, e.g., fructose) is drawn at the top, and the rest of the carbon atoms of the chain are drawn in sequence below the top carbon atom. For each carbon atom, depicted in projection as lying in the plane of the paper, the carbon-to-carbon bond(s), which actually point away from the viewer, are drawn as vertical lines. The left-hand and right-hand bonds of each carbon atom, which actually point toward the viewer, are, in projection, depicted as horizontal lines. The conventions for the Fischer formulas of cyclic sugars are as follows: 1) if the highest-numbered asymmetric carbon atom has its OH (or its replacement) lying to the right, as is the 2-OH of d-glyceraldehyde, the sugar has the d configuration; if the OH is to the left, the sugar has the l configuration. 2) On the anomeric carbon atom (C-1 in the aldoses; C-2 in the 2-ketoses), an OH or substituted OH that lies to the right, with the OH of the highest-numbered asymmetric carbon atom also to the right is defined to be a; if it is to the left, with the OH of the highest-numbered carbon atom still to the right, it is b; the reverse applies if the latter OH is to the left. 3) The orientation of a terminal CH2OH group in the aldoses carries no configurational significance, as it contains no asymmetric carbon atom. (05 Mar 2000) |
| lateral projection | Radiographic projection with the X-ray beam in a coronal plane. (05 Mar 2000) |
| frog-leg lateral projection | A lateral projection of the femoral neck made with the thigh maximally abducted. (05 Mar 2000) |
| abortion, recurrent | See Abortion, habitual. (12 Dec 1998) |
| anterior tibial recurrent artery | <anatomy, artery> A branch of the anterior tibial artery which ascends to supply the front and sides of the knee joint, thus contributing to the articular network of the knee. Synonym: arteria recurrens tibialis anterior. (05 Mar 2000) |
| radial recurrent artery | <anatomy, artery> Origin, radial; distribution, ascends around lateral side of elbow joint; anastomoses, radial collateral, interosseous recurrent. Synonym: arteria recurrens radialis, recurrent radial artery. (05 Mar 2000) |
| recurrent | Returning after intermissions. Origin: L. Recurrens = returning (18 Nov 1997) |
| recurrent albuminuria | A functional albuminuria sometimes observed intermittently in cycles of 12 to 36 hours' duration, chiefly in younger persons; the degree of albuminuria is usually slight. Synonym: recurrent albuminuria. (05 Mar 2000) |
| recurrent aphthous stomatitis | <dermatology> Roundish pearl-coloured specks or flakes in the mouth, on the lips, etc, terminating in white sloughs, better known as thrush and the specks are called aphthae. Synonym: thrush, candidiasis. Origin: Sing. Of Aphthae. L, fr. Gr. (mostly in pl, Hipp) an eruption, thrush, fr. To set on fire, inflame. (25 Jun 1999) |
| recurrent aphthous ulcers | <dermatology> Roundish pearl-coloured specks or flakes in the mouth, on the lips, etc, terminating in white sloughs, better known as thrush and the specks are called aphthae. Synonym: thrush, candidiasis. Origin: Sing. Of Aphthae. L, fr. Gr. (mostly in pl, Hipp) an eruption, thrush, fr. To set on fire, inflame. (25 Jun 1999) |
| recurrent appendicitis | Repeated episodes of right lower quadrant abdominal pain attributed to recurrence of inflammation of the appendix in an individual who did not have an appendectomy for prior episodes. Synonym: relapsing appendicitis. (05 Mar 2000) |
| recurrent artery | <anatomy, artery> An artery which, upon or soon after originating, reflects or turns sharply to course in the general opposite direction to that of its parent artery. Synonym: medial striate artery. (05 Mar 2000) |
| recurrent artery of Heubner | <anatomy, artery> Arises at or just distal to the anterior communicating artery; distribution: anterior caudate and putamen and anterior limb of internal capsule. Synonym: arteria centralis longa, arteria recurrens, artery of Heubner, long central artery, recurrent artery of Heubner, recurrent artery. (05 Mar 2000) |
| recurrent caries | Caries recurring in an area due to inadequate removal of the initial decay, usually beneath a restoration or new decay at a site where caries has previously occurred. (05 Mar 2000) |