| Lanterman's incisures | Funnel-shaped interruptions in the regular structure of the myelin sheath of nerve fibres, formerly interpreted as actual breaks in the sheath but shown by electron microscopy to correspond each to a strand of cytoplasm locally separating the two otherwise fused oligodendroglial (or, in peripheral nerves, Schwann cell) membranes composing the myelin sheath. Synonym: Lanterman's incisures, Schmidt-Lanterman clefts. (05 Mar 2000) |
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| Lanterman's segments | The divisions of the nerve fibre between the Schmidt-Lanterman incisures. (05 Mar 2000) |
| lantern | 1. Something inclosing a light, and protecting it from wind, rain, etc.; sometimes portable, as a closed vessel or case of horn, perforated tin, glass, oiled paper, or other material, having a lamp or candle within; sometimes fixed, as the glazed inclosure of a street light, or of a lighthouse light. 2. An open structure of light material set upon a roof, to give light and air to the interior. A cage or open chamber of rich architecture, open below into the building or tower which it crowns. A smaller and secondary cupola crowning a larger one, for ornament, or to admit light; such as the lantern of the cupola of the Capitol at Washington, or that of the Florence cathedral. 3. <machinery> A lantern pinion or trundle wheel. See Lantern pinion (below). 4. <engineering> A kind of cage inserted in a stuffing box and surrounding a piston rod, to separate the packing into two parts and form a chamber between for the reception of steam, etc.; called also lantern brass. 5. A perforated barrel to form a core upon. 6. <zoology> See Aristotle's lantern. Fig. 1 represents a hand lantern; fig. 2, an arm lantern; fig. 3, a breast lantern; so named from the positions in which they are carried. Dark lantern, a lantern with a single opening, which may be closed so as to conceal the light; called also bull's-eye. Lantern fly, Lantern carrier, any translucent, marine, bivalve shell of the genus Anatina, and allied genera. Magic lantern, an optical instrument consisting of a case inclosing a light, and having suitable lenses in a lateral tube, for throwing upon a screen, in a darkened room or the like, greatly magnified pictures from slides placed in the focus of the outer lens. Origin: F. Lanterne, L. Lanterna, laterna, from Gr. Light, torch. See Lamp. Source: Websters Dictionary (01 Mar 1998) |
| lanthanic | Rarely used term denoting a disease process that produces no symptoms or clinical evidence of illness. Origin: G. Lanthano, to lie hidden (05 Mar 2000) |
| lanthanides | Those elements with atomic numbers 57-71 which closely resemble one another chemically and were once difficult to separate from one another. Synonym: rare earth elements. Origin: Lanthanum, first element of the series (05 Mar 2000) |
| lanthanite | <chemical> Hydrous carbonate of lanthanum, found in tabular while crystals. Source: Websters Dictionary (01 Mar 1998) |
| lanthanum | <chemical> Lanthanum salts are used as a negative stain in electron microscopy and as calcium channel blockers. (18 Nov 1997) |
| lanthionine | S(CH2-CH(NH3)+-COO- )2; 3,3'-thiodialanine;an amino acid obtained from wood which resembles cystine but has only one sulfur atom in the molecule rather than two; i.e., a sulfide rather than a disulfide. (05 Mar 2000) |
| lanthionine synthase | <enzyme> Proposed complex of nisb, at least two molecules of nisc and a nist dimer; converts nisin prepeptide by a dehydratase reaction at serine and threonine, forming dehydroalanine and dehydrobutyrine, which are converted to thioethers with neighboring cysteine residues in lantibiotic prepeptides Registry number: EC 4.2.1.- (26 Jun 1999) |
| lanthopine | <chemistry> An alkaloid found in opium in small quantities, and extracted as a white crystalline substance. Origin: Gr. To lie hid + E. Opium. Source: Websters Dictionary (01 Mar 1998) |
| lanuginous | Covered with lanugo. (05 Mar 2000) |
| lanugo | <anatomy> The soft woolly hair which covers most parts of the mammal foetus, and in man is shed before or soon after birth. See: Lanuginose. Source: Websters Dictionary (01 Mar 1998) |
| lanugo hair | <anatomy> The soft woolly hair which covers most parts of the mammal foetus, and in man is shed before or soon after birth. See: Lanuginose. Source: Websters Dictionary (01 Mar 1998) |
| Lanz | Otto, Swiss surgeon in Amsterdam, 1865-1935. See: Lanz's line. (05 Mar 2000) |
| Lanz's line | A horizontal plane passing through the anterior superior iliac spines; it marks the boundary between the lateral and umbilical regions superiorly and the inguinal and pubic regions inferiorly. Synonym: planum interspinale, Lanz's line. (05 Mar 2000) |