| preprostate 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) |
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| prepyloric sphincter | A band of circular muscular fibres in the wall of the stomach near the gastroduodenal pylorus. (05 Mar 2000) |
| hepatopancreatic sphincter | The smooth muscle sphincter of the hepatopancreatic ampulla within the duodenal papilla. Synonym: musculus sphincter ampullae hepatopancreaticae, Glisson's sphincter, hepatopancreatic sphincter, Oddi's sphincter. (05 Mar 2000) |
| proximal 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) |
| segmental sphincter | A sphincter of a segment of an organ, a tube, or a canal, and longer than an annular sphincter. (05 Mar 2000) |
| pyloric sphincter | A thickening of the circular layer of the gastric musculature encircling the gastroduodenal junction. Synonym: musculus sphincter pylori, sphincter muscle of pylorus. (05 Mar 2000) |
| Hyrtl's sphincter | A band, generally incomplete, of circular muscular fibres in the rectum about 10 cm above the anus (upper rectal ampulla). See: Nelaton's sphincter. (05 Mar 2000) |
| smooth muscular sphincter | A sphincter of smooth musculature. Synonym: smooth muscular sphincter. Origin: G. Lissos, smooth, + sphincter (05 Mar 2000) |
| sphincter | <anatomy> A ringlike band of muscle fibres that constricts a passage or closes a natural orifice, also called musculus sphincter. Origin: L., Gr. Sphinkter = that which binds tight (18 Nov 1997) |
| sphincter angularis | Angular sphincter, thickening of the circular muscular layer forming a proposed intermediate sphincter at the level of the angular notch of the stomach. While the thickening of the circular muscle may indicate the commencement of the pyloric antrum, true functional sphincteric activity distinct from the other peristaltic contractions of the stomach is not observed although some of these may in fact temporarily close off the antrum from the remainder of the stomach lumen. Synonym: antral sphincter, midgastric transverse sphincter, sphincter antri, sphincter intermedius, sphincter of antrum, sphincter of gastric antrum. (05 Mar 2000) |
| sphincter ani tertius | The third sphincter of the anorectum, a physiological sphincter at the sigmoidorectal junction. (05 Mar 2000) |
| sphincter antri | Angular sphincter, thickening of the circular muscular layer forming a proposed intermediate sphincter at the level of the angular notch of the stomach. While the thickening of the circular muscle may indicate the commencement of the pyloric antrum, true functional sphincteric activity distinct from the other peristaltic contractions of the stomach is not observed although some of these may in fact temporarily close off the antrum from the remainder of the stomach lumen. Synonym: antral sphincter, midgastric transverse sphincter, sphincter antri, sphincter intermedius, sphincter of antrum, sphincter of gastric antrum. (05 Mar 2000) |
| sphincter constrictor cardiae | 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) |
| sphincter intermedius | Angular sphincter, thickening of the circular muscular layer forming a proposed intermediate sphincter at the level of the angular notch of the stomach. While the thickening of the circular muscle may indicate the commencement of the pyloric antrum, true functional sphincteric activity distinct from the other peristaltic contractions of the stomach is not observed although some of these may in fact temporarily close off the antrum from the remainder of the stomach lumen. Synonym: antral sphincter, midgastric transverse sphincter, sphincter antri, sphincter intermedius, sphincter of antrum, sphincter of gastric antrum. (05 Mar 2000) |
| sphincter muscle | <anatomy> A ringlike band of muscle fibres that constricts a passage or closes a natural orifice, also called musculus sphincter. Origin: L., Gr. Sphinkter = that which binds tight (18 Nov 1997) |