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law of Laplace

(lah-plhas′) [Pierre-Simon Laplace, Fr. scientist, 1749–1827] A law stating that pressure within a tube is inversely proportional to the radius. The larger the diameter of a tubular structure, the less chance that it will rupture when subjected to an increase in pressure.


A layer of microorganisms growing on a culture medium.


(lo-ren′sē-ŭm) [Ernest O. Lawrence, U.S. physicist, 1901–1958 + -ium] SYMB: Lr. A synthetic transuranic chemical element, atomic weight (mass) (most stable isotope) 260, atomic number 103.


(lăks) [L. laxus, slack] 1. Without tension. 2. Loose and not easily controlled; said of bowel movements.


(lăk′să-tĭv) [L. laxare, to loosen] A food or chemical substance that acts to loosen the bowels and prevent or treat constipation. Laxatives may act by increasing peristalsis by irritating the intestinal mucosa, lubricating the intestinal walls, softening the bowel contents by increasing the amount of water in the intestines, and increasing the bulk of the bowel contents. Many people feel that it is essential to have one or more bowel movements a day, and, if they do not, they may develop the habit of taking some form of laxative daily. They should be instructed that missing a bowel movement is not harmful and that bowel movements do not necessarily occur at regular intervals. SYN: aperient; cathartic; purgative. SEE: constipation; enema.

l. regimen A diet modified to avoid chronic constipation by eating high-bulk foods that contain a high fiber content, eating foods that tend to stimulate bowel activity, e.g., stewed fruits and vegetables, maintaining adequate fluid intake, and participating in regular exercise.


(lăk′sĭ-tē) [L. laxitas, openness] The amount a joint or ligament deviates from its initial position when a force is applied to it.


(lā′ĕr) A thin sheetlike structure of more or less uniform thickness. SEE: stratum.

basal l. The outermost layer of the uterine endometrium lying next to the myometrium. SYN: basilar l.

basilar l. Basal l.

clear l. The stratum lucidum of the epidermis. SEE: stratum lucidum.

columnar l. A layer of tall, narrow epithelial cells forming a covering or lining.

compact l. The dense surface layer of the uterine endometrium.

enamel l. The innermost layer the enamel organ. SYN: ameloblastic layer. SEE: enamel organ.

ependymal l. The inner layer of cells of the embryonic neural tube.

feeder l. A layer of connective tissue cells that are used to nourish cultured tissue cells in the laboratory. The ...

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