. Diseases of the rectum and anus: designed for students and practitioners of medicine. itudinal muscular fibers are prominent in thevalves. Sometimes the longitudinal muscle spans the baseof the valve; and, again, it splits, some fibers following thecircular coat and some spanning the base. In some instancesit extends well into the tip in all the valves. In regard to the function of the rectal valves, Penning-ton says: From experimental studies made upon the livingand the dead, it would seem that the function of these plicaeis (1) to prevent the feces from crowding down upon the anuswhen the
. Diseases of the rectum and anus: designed for students and practitioners of medicine. itudinal muscular fibers are prominent in thevalves. Sometimes the longitudinal muscle spans the baseof the valve; and, again, it splits, some fibers following thecircular coat and some spanning the base. In some instancesit extends well into the tip in all the valves. In regard to the function of the rectal valves, Penning-ton says: From experimental studies made upon the livingand the dead, it would seem that the function of these plicaeis (1) to prevent the feces from crowding down upon the anuswhen the bowel is in a passive state, (2) to equalize the press-ure of feces that may accumulate in the rectum from time totime, and (3) to facilitate defecation by giving a spiral motionto the fecal mass. He further believes that, as a result ofmechanic and infectious agencies, a sort of chronic inflam-mation may occur in the rectum favoring hyperplasia of thevalves, which sooner or later becomes a factor in chronic con-stipation or obstipation. He says: The intestinal wall is fre- PLHTE If. Rectum Out Dpen, showing Two Rectal Halves Situated Hlmast UirectlyOpposite, One Just Mhoue the Other, [Paraffin Cast, shown in Plate III,was Removed from this Specimen.] ANATOMY AND PHYSIOLOGY 35 quently pouched and thinned immediately above the base ofthe Valve/ and hypertrophied opposite the valves free bor-der. From the foregoing it will be seen that investigatorsdiffer widely in their conclusions as to the constancy, number,location, structure, and function of the rectal valves, and alsothat at the present time httle information on this subject isto be gained from text-books on either anatomy or writers on diseases of the rectum and anus fail to men-tion them, or, having mentioned them, ascribe but little or noimportance to their existence: opinions which are seeminglyfounded on clinic experience rather than on original research. In the previous edition of this work the author, af
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Keywords: ., bookcentury1900, bookdecade1910, booksubjectanusdis, bookyear1910
