| 释义 |
anal sphincter
Thesaurus| Noun | 1. | anal sphincter - the sphincter muscle of the anusmusculus sphincter ani, sphincter anianus - the excretory opening at the end of the alimentary canalanatomical sphincter, sphincter, sphincter muscle - a ring of muscle that contracts to close an openingmusculus sphincter ani externus - an external ring of striated muscle surrounding the anusmusculus sphincter ani internus - an internal ring of smooth muscle formed by circular fibers of the rectum |
anal sphincter
sphincter [sfingk´ter] a circular muscle that constricts a passage or closes a natural orifice. When relaxed, a sphincter allows materials to pass through the opening. When contracted, it closes the opening. Four main sphincter muscles along the alimentary canal aid in digestion: the sphincter" >cardiac sphincter, the sphincter" >pyloric sphincter, and two sphincters" >anal sphincters. Other sphincters are found in the iris of the eye, the bile duct (sphincter of Oddi" >sphincter of Oddi), the urinary tract, and elsewhere.anal sphincter (sphincter a´ni) either of two sphincters (the internal and external anal sphincters) that open and close to control evacuation of feces from the anus.cardiac sphincter a sphincter between the esophagus and the stomach, opening at the approach of food that can then be swept into the stomach by rhythmic peristaltic waves.sphincter of Oddi a sheath of muscle fibers investing the associated bile and pancreatic passages as they traverse the wall of the duodenum.pyloric sphincter a sphincter at the opening from the stomach into the duodenum; it is usually closed, opening only for a moment when a peristaltic wave passes over it.urinary sphincter, artificial a fluid-filled system that surrounds the urethra with a silicone cuff that functions as a sphincter; a pump is in the scrotum and a fluid reservoir is in the abdomen. For urination, the pump's release valve is squeezed to allow the fluid to leave the urethral cuff and return to the reservoir; after urination is complete, the pump is squeezed and the fluid returns to the cuff to occlude the urethra.ex·ter·nal a·nal sphinc·ter [TA] a fusiform ring of striated muscular fibers 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(s): musculus sphincter ani externus [TA], external sphincter muscle of anusanal sphincter A hybrid anatomic structure designed to control the anal opening, which is composed of an internal sphincter and an external spincter. Anal sphincter defects can be induced by forceps delivery.anal sphincter The double muscular ring surrounding the anal canal which, in conjunction with the thick, well-vascularized lining of the canal, produces a watertight seal except during defaecation.anal sphincter
Related to anal sphincter: hemorrhoid, sphincter ani, Sphincter ani externus muscleSynonyms for anal sphincternoun the sphincter muscle of the anusSynonyms- musculus sphincter ani
- sphincter ani
Related Words- anus
- anatomical sphincter
- sphincter
- sphincter muscle
- musculus sphincter ani externus
- musculus sphincter ani internus
|