. Diseases of the rectum and anus: designed for students and practitioners of medicine. he liver, it is easy to understand how obstructive hepatic dis-ease may cause a varicose condition of the veins in the lowerrectum. Constipation is perhaps the most frequent cause of hemor-rhoids. When defecation is deferred for a considerable timethe feces accumulate and become hard and nodular and diffi-cult to expel. If this large, hard mass is retained in the rectum,it presses upon the vessels, interferes with the circulation, andby bruising the vessels may induce a phlebitis. When the hard-ened feces a
. Diseases of the rectum and anus: designed for students and practitioners of medicine. he liver, it is easy to understand how obstructive hepatic dis-ease may cause a varicose condition of the veins in the lowerrectum. Constipation is perhaps the most frequent cause of hemor-rhoids. When defecation is deferred for a considerable timethe feces accumulate and become hard and nodular and diffi-cult to expel. If this large, hard mass is retained in the rectum,it presses upon the vessels, interferes with the circulation, andby bruising the vessels may induce a phlebitis. When the hard-ened feces are expelled, straining is intense, the mass closes thevessel above by pressure and forces the blood downward intothe veins, producing dilatation; when the force is sufficient, oneor more of the small veins near the anal outlet may ruptureand cause a vascular tumor beneath the mucosa or skin. PATHOLOGY The classification of hemorrhoids (piles) into internal andexternal is more important from a clinic than from a pathologicstand-point, because the changes which occur in the structures. PLATE XXIII.—8B0WING THE VASCULAR SUPPLY OF INTERNAL , Superior hemorrhoidal Veins. B, Middle hemorrhoidal veins. C,Inferior hemorrhoidal veins. D, Hemorrhoidal plexus hy removal of the mucousmembrane. E, Protruding internal hemorrhoids covered by mucosa. EXTERNAL AND INTERNAL HEMORRHOIDS 413 during the formation of both varieties of tumor are similar inmany respects. In order to follow these changes it is necessaryto have a comprehensive understanding of the venous circu-lation of the lower rectum (Plate XXIII). The small branches of the superior hemorrhoidal veinsanastomose with similar branches of the inferior hemorrhoidalvein in the lower inch and a half ( centimeters) of the rec-tum, in and about Morgagnis columns. The importance ofthis anastomosis will be appreciated when it is understood thatthese intercommunicating venous radicles are the connectinglinks which here unite t
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Keywords: ., bookcentury1900, bookdecade1910, booksubjectanusdis, bookyear1910
