| LM | lactic acid mineral [medium]; lactose malabsorption; laryngeal mask; laryngeal muscle; lateral malle... |
|---|---|
| long | longitudinal |
| LPC | late positive component; lipocortin; longitudinal primary care [program]; lysophosphatidylcholine |
| LS | lateral suspensor; left sacrum; left septum; left side; legally separated; leiomyosarcoma; length of... |
| L/S | lactase/sucrase [ratio]; lecithin/ sphingomyelin [ratio]; lipid/saccharide [ratio]; longitudinal sec... |
| longitudinal section | A section that is cut along the long axis of a structure. The opposite is a cross-section. (12 Dec 1998) |
|---|---|
| longitudinal sinus | See: inferior sagittal sinus, superior sagittal sinus. Longitudinal vertebral venous sinus, large, plexiform veins forming portions of the anterior internal vertebral venous plexus lying on the posterior surfaces of the vertebral bodies on either side of the posterior longitudinal ligament. Synonym: sinus vertebrales longitudinales. Luschka's sinus, venous sinus in the petrosquamous suture. (05 Mar 2000) |
| longitudinal studies | Studies in which variables relating to an individual or group of individuals are assessed over a period of time. (12 Dec 1998) |
| longitudinal study | <epidemiology> A study taking place over time. If individuals are followed, this is a longitudinal cohort study. If individuals are not followed, but classes (usually age classes) are restudied, this is a longitudinal cross-sectional study. The converse of a horizontal study. (05 Dec 1998) |
| longitudinal sulcus of heart | See: anterior interventricular groove, posterior interventricular groove. (05 Mar 2000) |
| longitudinal wave | <physics> Waves where the variation of the field is partially or totally in the direction of propagation (parallel to wavennumber, k [a vector]). Examples include sound waves and Langmuir waves. Contrasted with transverse waves, where the variation is perpendicular to the direction of propagation, such as light waves. (13 Nov 1997) |
| Aeby's plane | In craniometry, a plane perpendicular to the median plane of the cranium, cutting the nasion and the basion. (05 Mar 2000) |
| aperture plane | <microscopy> In a microscope adjusted for Koehler illumination, the conjugate planes that include the light source, the condenser iris diaphragm, the objective lens back aperture, and the eye point. Spaces in the aperture planes are the reciprocal of those in the field planes. (05 Aug 1998) |
| auriculo-infraorbital plane | A standard craniometric reference plane passing through the right and left porion and the left orbitale; drawn on the profile radiograph or photograph from the superior margin of the acoustic meatus to the orbitale. Synonym: auriculo-infraorbital plane, eye-ear plane, Frankfort horizontal plane, Frankfort plane, infraorbitomeatal plane. (05 Mar 2000) |
| axial plane | Transverse plane, as in CT scanning. Synonym: transaxial plane. (05 Mar 2000) |
| axiolabiolingual plane | A plane parallel to the long axis of a tooth and extending in a labiolingual direction. (05 Mar 2000) |
| axiomesiodistal plane | A plane parallel to the long axes of the teeth and extending in a mesiodistal direction. (05 Mar 2000) |
| back focal plane | <microscopy> The plane, normal to the lens axis, situated at the back focus of a lens. (05 Aug 1998) |
| bite plane | <dentistry> A removable appliance made of acrylic designed to open a deep bite. See: occlusal plane. (06 Mar 2000) |
| Bolton-Broadbent plane | A roentgenographic cephalometric plane extending from the Bolton point to nasion. Synonym: Bolton-Broadbent plane, Bolton-nasion line, Bolton-nasion plane. (05 Mar 2000) |