| rectal columns | A number of vertical ridges in the mucous membrane of the upper half of the anal canal formed as the caliber of the canal is sharply reduced from that of the rectal ampulla. Synonym: columnae anales, Morgagni's columns, rectal columns. (05 Mar 2000) |
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| rectal fistula | Abnormal passage communicating with the rectum. (12 Dec 1998) |
| rectal folds | The three or four crescentic folds placed horizontally in the rectal mucous membrane; the superior rectal fold is situated near the beginning of the rectum on the left side; the middle rectal fold (Nelaton's fold) is most prominent and consistent and projects from the right side about 8 cm above the anus (approximately the level of the floor of the rectouterine or rectovesical pouch); the inferior rectal fold is on the left side about 5 cm above the anus. Synonym: plicae transversales recti, Houston's folds, Houston's valves, Kohlrausch's valves, plicae recti, rectal folds, rectal valves. (05 Mar 2000) |
| rectal plexuses | See: inferior rectal plexuses, middle rectal plexuses, superior rectal plexus. (05 Mar 2000) |
| rectal prolapse | Protrusion of the rectal mucous membrane through the anus. There are various degrees: incomplete with no displacement of the anal sphincter muscle; complete with displacement of the anal sphincter muscle; complete with no displacement of the anal sphincter muscle but with herniation of the bowel; and internal complete with rectosigmoid or upper rectum intussusception into the lower rectum. (12 Dec 1998) |
| rectal reflex | The entrance of faecal matter into the rectum from the sigmoid colon causes an impulse to defecate. (05 Mar 2000) |
| rectal shelf | A shelf palpable by rectal examination, due to metastatic tumour cells gravitating from an abdominal cancer and growing in the rectovesical or rectouterine pouch. Synonym: Blumer's shelf. (05 Mar 2000) |
| rectal sinuses | The grooves between the anal columns. Synonym: Morgagni's sinus. Pockets or crypts in the columnar zone of the anal canal between the anocutaneous line and the anorectal line; the sinuses give the mucosa a scalloped appearance. Synonym: sinus anales, anal crypts, Morgagni's crypts, rectal sinuses. (05 Mar 2000) |
| rectal valves | The three or four crescentic folds placed horizontally in the rectal mucous membrane; the superior rectal fold is situated near the beginning of the rectum on the left side; the middle rectal fold (Nelaton's fold) is most prominent and consistent and projects from the right side about 8 cm above the anus (approximately the level of the floor of the rectouterine or rectovesical pouch); the inferior rectal fold is on the left side about 5 cm above the anus. Synonym: plicae transversales recti, Houston's folds, Houston's valves, Kohlrausch's valves, plicae recti, rectal folds, rectal valves. (05 Mar 2000) |
| rectal valvotomy | Cutting through rectal folds that are too rigid or large. (05 Mar 2000) |
| rectal venous plexus | A venous plexus resting upon the posterior and lateral walls of the rectum; it drains into the superior rectal vein to the portal, the middle rectal to the internal iliac and the inferior rectal to the internal pudendal. Synonym: plexus venosus rectalis, haemorrhoidal plexus. (05 Mar 2000) |
| superior rectal artery | <anatomy, artery> Origin, inferior mesenteric; distribution, upper part of rectum; anastomoses, middle and inferior rectal. As a tributary of the portal vein, its anastomosis with these arteries forms a portosystemic or portocaval anastomosis. Synonym: arteria rectalis superior, superior haemorrhoidal artery. (05 Mar 2000) |
| superior rectal plexus | The autonomic plexus derived as a continuation of the inferior mesenteric plexus that accompanies the superior rectal artery. Synonym: plexus rectalis superior, superior haemorrhoidal plexus. (05 Mar 2000) |
| superior rectal vein | <anatomy, vein> It drains the greater part of the rectal venous plexus, and ascends between the layers of the mesorectum to the brim of the pelvis, where it becomes the inferior mesenteric vein. As a tributary of the portal vein, it forms a portocaval anastomosis with the middle and inferior rectal veins (caval tributaries) via the rectal venous plexus. Synonym: vena rectalis superior. (05 Mar 2000) |
| digital rectal exam | An exam to detect rectal cancer. The doctor inserts a lubricated, gloved finger into the rectum and feels for abnormal areas. It is also an important screening test for the detection of prostate abnormalities, including cancer. (12 Dec 1998) |