. American practice of surgery ; a complete system of the science and art of surgery . ouston * firet described these folds as valves of the rectum. They vary innumber from one to five. Ordinarily there are three—the superior, the middle, * Dublin Hospital Reports, 1830, vol. v., p. 762 AMERICAN PRACTICE OF SURGERY. and the inferior. The middle one is the most constant. It arises from theright anterior quadrant of the rectal wall, about 6 to 9 centimetres abovethe margin of the anus. It varies in height according to the depth of the peri-toneal cul-de-sac, being always just below the l
. American practice of surgery ; a complete system of the science and art of surgery . ouston * firet described these folds as valves of the rectum. They vary innumber from one to five. Ordinarily there are three—the superior, the middle, * Dublin Hospital Reports, 1830, vol. v., p. 762 AMERICAN PRACTICE OF SURGERY. and the inferior. The middle one is the most constant. It arises from theright anterior quadrant of the rectal wall, about 6 to 9 centimetres abovethe margin of the anus. It varies in height according to the depth of the peri-toneal cul-de-sac, being always just below the latter. The inferior valve islocated upon the left posterior quadrant, from 25 to 30 millimetres above themargin of the anus, and the superior valve is located in the same quadrant,about 8 to 11 cm. above the anus. (Fig. 304.) At the juncture of the rectumwith the sigmoid flexure, opposite the third sacral vertebra, there is always awell-developed fold or valve, which more nearly occludes the cahbre of theorgan than does either of the others. It is situated somewhat anteriorly and. Fig. 304.—The Drawing Shows the Positions of Houstons and the Semilunar Valves. to the right or left side according to the direction of the flexure of thesigmoid upon the rectum. The rectal valves protrude into the cavity of the organ to various are attached to the wall of the intestine throughout one-third to one-half of its circumference; they are crescentic in shape, and present for con-sideration two surfaces, a free border, a base, and a central body. The superiorsurface of each valve appears as a smooth, inclined plane, slightly depressedin the centre, and the inferior surface corresponds to the superior, being moreor less convex according to the concavity of the latter. The two surfaces areseparated, the one from the other, by the tissues which intervene, viz., themucous membrane and the tissues which compose the structure of the valve. SURGICAL DISEASES OF THE ANUS AND RECTUM.
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Keywords: ., bookcentury1900, bookdecade1900, booksubjectsurgery, bookyear1906
