| 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... |
| LSect | longitudinal section |
| LSV | lateral sacral vein; left subclavian vein; longitudinal sound velocity |
| MLF | medial longitudinal fasciculus; morphine-like factor |
calcarine sulcus
| 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 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) |
| abnormal heart chamber dimensions | <radiology> Left ventricular volume overload, left ventricular hypertrophy, right ventricular volume overload, right ventricular hypertrophy, fixed subvalvular aortic stenosis, hypoplastic left/right ventricle; common ventricle, congestive cardiomyopathy (12 Dec 1998) |
| Abrams' heart reflex | A contraction of the myocardium when the skin of the precordial region is irritated. (05 Mar 2000) |
| american heart association | A voluntary organization concerned with the prevention and treatment of heart and vascular diseases. (12 Dec 1998) |
| apex of heart | The blunt extremity of the heart formed by the left ventricle. See: apex beat. Synonym: apex cordis, vertex cordis. (05 Mar 2000) |
| armored heart | Calcareous deposits in the pericardium due to subacute or chronic pericarditis. Synonym: panzerherz. (05 Mar 2000) |
| armor heart | Extensive to complete calcification (rarely ossification) of the pericardium usually producing constrictive pericarditis. (05 Mar 2000) |
| artificial heart | A mechanical pump used to replace the function of a damaged heart, either temporarily or as a permanent prosthesis. (05 Mar 2000) |
| artificial heart valve | <cardiology> A synthetic or porcine (pigskin) valve surgically placed into the heart to replace a defective or malfunctioning valve. The aortic and mitral valves are the most frequently replaced with artificial valves. (27 Sep 1997) |
| athlete's heart | A more or less loose designation for cardiac findings in healthy athletes that would be or could be abnormal in patients with disease, including atrioventricular blocks, left ventricular hypertrophy and, sometimes, benign arrhythmias and atrioventricular blocks. (05 Mar 2000) |
| athletic heart | Hypertrophy of the heart supposedly due to systematic athletic conditioning. (05 Mar 2000) |