| false projection | <ophthalmology> The faulty visual sensation arising secondarily to underaction of an ocular muscle. Synonym: erroneous projection. (05 Mar 2000) |
|---|---|
| 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) |
| acoustic area | The floor of the lateral recess of the fourth ventricle, extending medially to the limiting sulcus and overlying the cochlear and vestibular nuclei of the rhombencephalon. Synonym: area acustica. (05 Mar 2000) |
| adaptive management area | Landscape units designated for development and testing of technical and social approaches to achieving desired ecological, economic, and other social objectives. (05 Dec 1998) |
| air quality maintenance area | Specific populated area where air quality is a problem for one or more pollutants (Portland-Vancouver, Salem, Eugene-Springfield, Medford-Ashland). (05 Dec 1998) |
| anterior intercondylar area of tibia | The broad depressed area between the tibial condyles anteriorly to which attach the anterior ends of the menisci and the anterior cruciate ligament. Synonym: area intercondylaris anterior tibiae. (05 Mar 2000) |
| aortic area | The region of the chest wall over the second right costal cartilage, where sounds produced at the aortic orifice are often best heard. (05 Mar 2000) |
| apical area | The area about the root end of a tooth. (05 Mar 2000) |
| area | Origin: L. Area a broad piece of level gro. Cf. Are. 1. Any plane surface, as of the floor of a room or church, or of the ground within an inclosure; an open space in a building. "The Alban lake . . . Looks like the area of some vast amphitheater." (Addison) 2. The inclosed space on which a building stands. 3. The sunken space or court, giving ingress and affording light to the basement of a building. 4. An extent of surface; a tract of the earth's surface; a region; as, vast uncultivated areas. 5. <geometry> The superficial contents of any figure; the surface included within any given lines; superficial extent; as, the area of a square or a triangle. 6. <biology> A spot or small marked space; as, the germinative area. 7. Extent; scope; range; as, a wide area of thought. "The largest area of human history and man's common nature." (F. Harrison) Dry area. See Dry. Source: Websters Dictionary (01 Mar 1998) |
| area acustica | The floor of the lateral recess of the fourth ventricle, extending medially to the limiting sulcus and overlying the cochlear and vestibular nuclei of the rhombencephalon. Synonym: area acustica. (05 Mar 2000) |
| area centralis | 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) |
| area cochleae | The area inferior to the transverse crest of the fundus of the internal acoustic meatus through which the filaments of the cochlear nerve pass to enter the cochlea; forms the base of the cone-shaped modiolus about which the cochlear canal spirals. See: base of modiolus. Synonym: area cochleae. (05 Mar 2000) |
| area cribrosa papillae renalis | The apex of a renal papilla pierced by 10 to 22 openings of the papillary ducts, the foramina papillaria. Synonym: area cribrosa papillae renalis. (05 Mar 2000) |