sphincter

(sfink'tur) [G. sphinktSr, a. band or lace.] An orbicular muscle which serves, when in a state of normal contraction, to close one of the orifices of the body, pre pyloric s., a band of circular muscular fibers in the wall of the stomach near the pylorus, the contraction of which during digestion forms the antrum pylori cum. pylor'ic s., a circular thickening of the muscular wall of the stomach surroiuiding the pyloric orifice, s. ani, see under musculus. s, oc'uli, musculus orbicularis oculi. s. o'ris, musculus orbicularis or is. s. ure'thrse, see under musculus. s. vagi'nae, musculus bulbocavemosus. s. vesi'cse, annulus urethral is.