| LSV | lateral sacral vein; left subclavian vein; longitudinal sound velocity |
|---|---|
| MLF | medial longitudinal fasciculus; morphine-like factor |
| MLS | mean lifespan; median life span; median longitudinal section; microphthalmia-linear skin defects [sy... |
| Mz | longitudinal magnetization |
| OALL | ossification of anterior longitudinal ligament |
| longitudinal method | In developmental psychology, the study of the life span of one individual involving comparisons of different age levels. Compare: cross-sectional method. (05 Mar 2000) |
|---|---|
| longitudinal oval pelvis | A pelvis in which the anteroposterior diameter is longer than the transverse. Synonym: longitudinal oval pelvis. (05 Mar 2000) |
| longitudinal pontine bundles | The massive bundles of corticofugal fibres passing longitudinally through the ventral part of pons; they are composed of corticopontine, corticobulbar, and corticospinal fibres. Synonym: fasciculi longitudinales pontis, longitudinal pontine bundles. (05 Mar 2000) |
| longitudinal pontine fasciculi | The massive bundles of corticofugal fibres passing longitudinally through the ventral part of pons; they are composed of corticopontine, corticobulbar, and corticospinal fibres. Synonym: fasciculi longitudinales pontis, longitudinal pontine bundles. (05 Mar 2000) |
| longitudinal relaxation | In nuclear magnetic resonance, the return of the magnetic dipoles of the hydrogen nuclei (magnetization vector) to equilibrium parallel to the magnetic field, after they have been flipped 90 |
| 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) |
| adult pseudohypertrophic muscular dystrophy | Muscular dystrophy of late onset, often in the second or third decade, with relatively mild course; X-linked recessive inheritance; perhaps allelic with Duchenne's dystrophy, but milder and not a genetic lethal. Compare: Duchenne dystrophy. Synonym: Becker type tardive muscular dystrophy. (05 Mar 2000) |
| Becker's muscular dystrophy | An X-linked inherited disorder characterised by slowly progressive muscle weakness of the legs and pelvis. Other symptoms and findings include increased difficulty walking, intellectual retardation, fatigue and pseudohypertrophy of the calf muscles. (27 Sep 1997) |
| Becker type muscular dystrophy | A muscular dystrophy that has many of the clinical features of Duchenne muscular dystrophy e.g., symmetrical involvement of first the pelvicrural muscles and then the pectoral girdle and proximal upper extremity muscles; pseudohypertrophy, especially of the calf muscles but with a much later age of onset (35-45 years), and more benign course. X-linked inheritance. (05 Mar 2000) |
| Becker type tardive muscular dystrophy | Muscular dystrophy of late onset, often in the second or third decade, with relatively mild course; X-linked recessive inheritance; perhaps allelic with Duchenne's dystrophy, but milder and not a genetic lethal. Compare: Duchenne dystrophy. Synonym: Becker type tardive muscular dystrophy. (05 Mar 2000) |