sphincter muscle of pupil n.
A ring of smooth muscle fibers surrounding the pupillary border of the iris.
- Sphincter muscle of pylorus
sphincter muscle of pylorus n. See pyloric sphincter.
- Sphincter muscle of urethra
sphincter muscle of urethra n. A muscle with origin from the ramus of the pubis, wih insertion with its fellow muscle in the median raphe behind and in front of the urethra, with nerve supply from the pudendal nerve, and whose action constricts the membranous urethra.
- Sphincter muscle of urinary bladder
sphincter muscle of urinary bladder n. A vesical sphincter made up of a thickening of the middle muscular layer of the bladder around the urethral opening. Also called sphincter muscle of urinary bladder.
sphincterolysis sphinc·ter·ol·y·sis (sfĭngk’tə-rŏl’ĭ-sĭs) n. An operation to correct anterior synechia.