| line | 1. The course followed by anything in motion; hence, a road or route; as, the arrow descended in a curved line; the place is remote from lines of travel. 2. <mathematics> That which has length, but not breadth or thickness. 3. <geography> A circle of latitude or of longitude, as represented on a map. The equator; usually called the line, or equinoctial line; as, to cross the line. 4. <genetics> A series or succession of ancestors or descand ants of a given person; a family or race; as, the ascending or descending line; the line of descent; the male line; a line of kings. "Of his lineage am I, and his offspring By very line, as of the stock real." (Chaucer) 5. <physics> Line of force, any line in a space in which forces are acting, so drawn that at every point of the line its tangent is the direction of the resultant of all the forces. It cuts at right angles every equipotential surface which it meets. Specifically, the outline of a horizontal section of a vessel, as when floating in the water. Origin: OE. Line, AS. Line cable, hawser, prob. From L. Linea a linen thread, string, line, fr. Linum flax, thread, linen, cable; but the English word was influenced by F. Ligne line, from the same L. Word linea. Source: Websters Dictionary (01 Mar 1998) |
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| line angle | In dentistry, the junction of two surfaces of the crown of a tooth, or of a tooth cavity (cavity line angle). (05 Mar 2000) |
| line for soleus muscle | A ridge which extends obliquely downward and medially across the back of the tibia from the fibular articular facet; it gives origin to the soleus muscle. Synonym: linea musculi solei, line for soleus muscle, linea poplitea, popliteal line. (05 Mar 2000) |
| line of Bechterew | A band of horizontal myelinated fibres in the most superficial part of the third layer of the isocortex. Synonym: Bechterew's band, layer of Bechterew, line of Bechterew, line of Kaes. (05 Mar 2000) |
| line of demarcation | A zone of inflammatory reaction separating a gangrenous area from healthy tissue. (05 Mar 2000) |
| line of fixation | A line joining the object (or point of fixation) with the fovea. (05 Mar 2000) |
| line of Gennari | A prominent white line appearing in perpendicular sections of the visual cortex (Brodmann's area 17) at about mid-thickness of the cortical gray matter, corresponding to the particularly well developed outer line of Baillarger of that cortical area, and composed largely of tangentially disposed intracortical association fibres. Synonym: Gennari's band, Gennari's stria, stripe of Gennari. (05 Mar 2000) |
| line of Kaes | A band of horizontal myelinated fibres in the most superficial part of the third layer of the isocortex. Synonym: Bechterew's band, layer of Bechterew, line of Bechterew, line of Kaes. (05 Mar 2000) |
| line of occlusion | The alignment of the occluding surfaces of the teeth in the horizontal plane. See: occlusal plane. (05 Mar 2000) |
| line of vision | The straight line extending from the object seen, through the centre of the pupil, to the macula lutea of the retina. Synonym: line of vision. (05 Mar 2000) |
| line pairs | A unit of resolution of radiographic screens and films or photographic films. (05 Mar 2000) |
| line precedence | <zoology> When two different names for the same taxon are first published in the same publication, then the one which appears on the earlier line has line precedence. Line precedence does not necessarily mean priority as well - this is determined by the action of the first reviser. (09 Jan 1998) |
| line spread function | A measure of the ability of a system to form sharp images; in radiology, determined by measuring the spatial density distribution on film of the X-ray image of a narrow slit in a dense metal, such as uranium; from this can be calculated the modulation transfer function. (05 Mar 2000) |
| line test | A test for rickets, based on observation of the lines of calcification in the growing ends of rachitic long bones in rats given vitamin D preparations under standard test conditions; used in biological assay of vitamin D by the USP. (05 Mar 2000) |
| line-tying | <radiobiology> Connection of field lines from the end of an open-ended device (such as a mirror system) to a conducting plate. The rigidity of field lines trapped in the plate can be transferred to the high-field region of the mirror by using a cold, moderately-dense plasma in between. Line-tying helps to stabilise against interchange instabilities. (09 Oct 1997) |
| alveolonasal line | A line connecting the alveolar point and the nasion. (05 Mar 2000) |
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| Amberg's lateral sinus line | A line dividing the angle formed by the anterior edge of the mastoid process and the temporal line. (05 Mar 2000) |
| anocutaneous line | The line between the simple columnar epithelium of the rectum and the stratified epithelium of the anal canal. Synonym: linea anocutanea, anocutaneous line, dentate line. (05 Mar 2000) |
| anterior axillary line | A vertical line extending inferiorly from the anterior axillary fold. Synonym: linea axillaris anterior, linea preaxillaris, preaxillary line. (05 Mar 2000) |
| anterior junction line | Radiographic projection of the mediastinal tissue septum between the upper lobes behind the sternum. (05 Mar 2000) |
| anterior median line | The line of intersection of the midsagittal plane with the anterior surface of the body. Synonym: linea mediana anterior. (05 Mar 2000) |
| arcuate line | An arching or bow-shaped line. See: arcuate line of ilium, arcuate line of rectus sheath. Synonym: linea arcuata. (05 Mar 2000) |
| arcuate line of ilium | The iliac portion of the linea terminalis of the bony pelvis. Synonym: linea arcuata ossis ilii. (05 Mar 2000) |
| arcuate line of rectus sheath | A crescentic line, not always clearly defined, which marks the lower limit of the posterior layer of the sheath of the rectus abdominis muscle. Synonym: linea arcuata vaginae musculi recti abdominis, Douglas' line, linea saemicircularis, saemicircular line. (05 Mar 2000) |
| arterial line | An intra-arterial catheter. (05 Mar 2000) |
| axillary line | See: anterior axillary line, midaxillary line, posterior axillary line. (05 Mar 2000) |
| basinasal line | A line connecting the basion and the nasion. Synonym: nasobasilar line. (05 Mar 2000) |
| Becke line | <microscopy> When the liquid phase of a microscopical mount has arefractive index different from that of the solid phase, a line or narrow band of light can be observed around or just within the outlines of the specimen as the microscope tube is raised or lowered from its position of best focus. The presence of the line indicates the difference in index referred to, and its absence, there-fore, indicates similarity of index between the specimen and its mounting fluid. The Becke line is useful in determining the refractive index of transparent, microscopic particles. (05 Aug 1998) |
| bismuth line | A black zone on the free marginal gingiva, often the first sign of poisoning from prolonged parenteral administration of bismuth. (05 Mar 2000) |
| black line | The linea alba in pregnancy, which then becomes pigmented. Synonym: black line. (05 Mar 2000) |