VALVE

n. Vaalv. Lat., valva. Fr., panneau. Ger., Valvel, Ventil, Klappe. 1. A movable flap or fold which acts to close a pa age or orifice more or le completely, [a, 48.] 2. In botany, a separable part in various organs, especially one of the pieces into which a dehiscent pericarp splits. The name has also been applied to the halves of a silicifled membrane in the Diatomacece, to the pieces of a glume, to the divisions of a spathe, to the volva in Fungi (by Paulet), and to the cotyledons (valvce seminum) of seeds (by Jungius). [a, 35.1 Aortic v. The v. situated at the exit of the aorta from the heart. It consists of three semilunar segments, which prevent the reflux of the blood into the heart. [L.] Bicuspid v. See Mitral v. Cerebral v. See V. of Vieu ens. Eustachian v. A crescentic fold of the lining structure of the total heart so situated as to direct the blood entering the right auricle by the vena cava inferior toward the opening of the foramen ovale. In the adult it may be obliterated, may be reduced to a trace, or may persist nearly as in the foetus. [A, 5.] Hasner's v. A mucous fold at the nasal aperture of the nasal duct. [L.] Heister's v. A v. formed by folds of the mucous membrane'of the neck of the gall-bladder. [L, 332.] Houston's v's. In the rectum, oblique folds of the mucous membrane, situated one at about the level of the prostate gland, another a little higher, and a third still higher. [L, 142.] Huschke's v. See VALVULA sacci lacrimal is superior. Ileo-caecal v., Ileo-colic v. Ger., Dickdarmklappe, Blinddarmklappe. An incomplete partition divided by a narrow slit-like opening, which is rounded anteriorly and narrow and pointed posteriorly, through which the cavities of the ileum and colon communicate. It is made up of the mucous membrane, its submucosa, and a few muscular fibres. It is nearly at right angles to the long axis of the colon, toward which one surface faces, the other facing toward the ileum. [L.] Inter auricular v. See V. of the foramen ovale. Large v. of the brain. See V. of Vieu ens. Mitral v. A v. situated at the left auriculoventricular opening, consisting of two more or le jointed segments continuous at their attached borders. [L, 31, 142, 332.] Pulmonary v. The v. in the left ventricle of the heart, at the entrance of the pulmonary artery. It consists of three semilunar segments, and prevents reflux of blood from the heart into the artery. [L.] Pyloric v. Ger., unterer Magenmundring. A ring-like elevation of the mucous membrane of the stomach around the pylorus IL, 31.] Semilunar aortic v. See Aortic v. Semilunar pulmonary v. See Pulmonary v. Semilunar (or Sigmoid) v's of the heart. Those v's of the heart which consist of three semilunar segments attached by their convex borders. [L.] Tricuspid v. A v., made up of three triangular segments, situated at the right auriculo-ventricular opening. [L.] V. of Amu at. See Heister's v. V's of a vein. Ger., Flilgelthiiren, Venenklappen. Semilunar folds of the inner coat of the veins, strengthened by connective ti ue, with their concave side placed like the inside of a pouch toward the heart, so that when they are filled they retard the backward flow of the blood. fC.] V. of Bauhin. See Ileo-ccecal v. V's of Kerkring. See VALVULA conniventes. \, of The bas i us. A semicircular fold of the endocardium at the entrance of the coronary sinus into the heart. [L, 142, 332.] V. of the colon. See Ileo-ccecal v. V. of the cystic duct. See Heister's v.\r. of A, ape; A", at; A3, ah; A4, all; Ch, chin; Ch, loch (Scottish); [s. 688]