| dilator muscle of ileocaecal sphincter | The longitudinal muscular fibres that open the ileal orifice at the level of the caecocolic junction. Synonym: musculus dilator pylori ilealis. (05 Mar 2000) |
|---|---|
| duodenal sphincter | One of the physiological sphincter's described in the duodenum. (05 Mar 2000) |
| duodenojejunal sphincter | The sphincter supposedly present at the duodenojejunal flexure. (05 Mar 2000) |
| ileal sphincter | A thickening of circular musculature at the free margin of the ileal papilla. Synonym: ileocaecocolic sphincter, marginal sphincter, operculum ilei, Varolius' sphincter. (05 Mar 2000) |
| ileocaecocolic sphincter | A thickening of circular musculature at the free margin of the ileal papilla. Synonym: ileocaecocolic sphincter, marginal sphincter, operculum ilei, Varolius' sphincter. (05 Mar 2000) |
| iliopelvic sphincter | The physiological sphincter midway in the sigmoid colon. Synonym: iliopelvic sphincter. (05 Mar 2000) |
| inferior oesophageal sphincter | A sphincter supposedly present at the oesophagogastric junction; this is in fact an extrinsic sphincter formed by the surrounding musculature of the oesophageal hiagus of the right crus of the diaphragm; causes a normally-occuring constriction at the oesophagogastric junction observable with a barium swallow. Synonym: sphincter constrictor cardiae. (05 Mar 2000) |
| internal anal sphincter | <anatomy> A smooth muscle ring, formed by an increase of the circular fibres of the rectum, situated at the upper end of the anal canal, internal to the outer voluntary external anal sphincter. This sphincter is maximally-contracted when the rectal ampulla is at rest -empty or relaxed to accommodate a distending faecal mass. It is inhibited with filling of the ampulla, increased distension and peristalsis. Synonym: musculus sphincter ani internus, internal sphincter muscle of anus. (05 Mar 2000) |
| internal sphincter muscle of anus | <anatomy> A smooth muscle ring, formed by an increase of the circular fibres of the rectum, situated at the upper end of the anal canal, internal to the outer voluntary external anal sphincter. This sphincter is maximally-contracted when the rectal ampulla is at rest -empty or relaxed to accommodate a distending faecal mass. It is inhibited with filling of the ampulla, increased distension and peristalsis. Synonym: musculus sphincter ani internus, internal sphincter muscle of anus. (05 Mar 2000) |
| internal urethral sphincter | The complete collar of smooth muscle cells of the neck of the urinary bladder which extend distally to surround the preprostatic sportion of the male urethra. There is not a comparable structure in the neck of the femoral bladder; the internal urethral sphincter may exist to prevent reflux of semen into bladder. Synonym: annulus urethralis, internal urethral sphincter, musculus sphincter vesicae, preprostate urethral sphincter, proximal urethral sphincter, sphincter muscle of urinary bladder. (05 Mar 2000) |
| intrinsic sphincter | A thickening of the circular fibres of the muscular coat of an organ. (05 Mar 2000) |
| O'Beirne's sphincter | <anatomy> A circular band of muscular fibres at the recto sigmoid junction. Synonym: O'Beirne's sphincter, O'Beirne's valve, pelvirectal sphincter. (05 Mar 2000) |
| oddi's sphincter | An annular sheath of muscle that invests the bile duct within the wall of the duodenum. (12 Dec 1998) |
| ostial sphincter | A thickening of circular muscular fibres at the level of an orifice. (05 Mar 2000) |
| external anal sphincter | A fusiform ring of striated muscular fibres surrounding the anus, attached posteriorly to the coccyx and anteriorly to the central tendon of the perineum; it is subdivided, often indistinctly, into a subcutaneous part, a superficial part and a deep part for descriptive purposes. Synonym: musculus sphincter ani externus, external sphincter muscle of anus. (05 Mar 2000) |