| LFL | left frontolateral; leukocyte feeder layer; lower flammable limit |
|---|---|
| NFL | nerve fiber layer; neurofilament protein, light polypeptide |
| NFLD | nerve fiber layer defect |
| OPL | other party liability; outer plexiform layer; ovine placental lactogen |
| PL | palmaris longus; pancreatic lipase; perception of light; peroneus longus; phospholipase; phospholipi... |
| 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) |
| lymphatic ring of cardiac part of stomach | A group of lymph nodes surrounding the cardia of the stomach. Synonym: annulus lymphaticus cardiae, cardiac lymphatic ring. (05 Mar 2000) |
| 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) |
| benign pseudohypertrophic muscular dystrophy | <neurology> 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. (06 Aug 1998) |
| pelvofemoral muscular dystrophy | One of the less well-defined types of muscular dystrophy, probably heterogenous in nature. Onset usually in childhood or early adulthood and both sexes affected. Characterised by weakness and wasting, usually symmetrical, of the pelvic girdle muscles, the shoulder girdle muscles, or both, but not the facial muscles. Muscle pseudohypertrophy, heart involvement, and mental retardation are absent. Variable inheritance. Synonym: Leyden-Mobius muscular dystrophy, pelvofemoral muscular dystrophy, scapulohumeral muscular dystrophy. (05 Mar 2000) |
| childhood muscular dystrophy | The most common childhood muscular dystrophy, with onset usually before age 6. Characterised by symmetrical weakness and wasting of first the pelvic and crural muscles and then the pectoral and proximal upper extremity muscles; pseudohypertrophy of some muscles, especially the calf; heart involvement; sometimes mild mental retardation; progressive course and early death, usually in adolescence. X-linked inheritance (affects males and transmitted by females). Synonym: childhood muscular dystrophy, Duchenne's disease, pseudohypertrophic muscular dystrophy. (05 Mar 2000) |
| peroneal muscular atrophy | A group of three familial peripheral neuromuscular disorders, sharing the common feature of marked wasting of the more distal extremities, particularly the peroneal muscle groups, resulting in "stork legs." Two of the three subtypes are hereditary sensorimotor polyneuropathies, one demyelinating in type and the other axon loss in type, while the third subgroup is an anterior horn cell disorder. It usually involves the legs before the arms; pes cavus is often the first sign; autosomal dominant, autosomal recessive, and X-linked recessive types, with severity related to genetic type. Synonym: Charcot-Marie-Tooth disease. (05 Mar 2000) |