pyloric sphincter

sphincter /sphinc·ter/ (sfingk´ter) [L.] a ringlike muscle which closes a natural orifice or passage.sphinc´teralsphincter´ic

---

anal sphincter , sphincter a´ni sphincter muscle of anus (external or internal).

cardiac sphincter , cardioesophageal sphincter muscle fibers about the opening of the esophagus into the stomach.

external sphincter of female urethra  external sphincter muscle of female urethra.

external sphincter of male urethra  external sphincter muscle of male urethra.

gastroesophageal sphincter  the terminal few centimeters of the esophagus, which prevents reflux of gastric contents into the esophagus.

hepatic sphincter  a thickened portion of the muscular coat of the hepatic veins near their entrance into the inferior vena cava.

internal sphincter of urethra  internal sphincter muscle of urethra.

O'Beirne's sphincter  a band of muscle at the junction of the sigmoid colon and rectum.

sphincter of Oddi  the sheath of muscle fibers investing the associated bile and pancreatic passages as they traverse the wall of the duodenum.

pharyngoesophageal sphincter  a region of higher muscular tone at the junction of the pharynx and esophagus, which is involved in movements of swallowing.

precapillary sphincter  a smooth muscle fiber encircling a true capillary where it originates from the arterial capillary, which can open and close the capillary entrance.

pyloric sphincter  see under muscle.

rectal sphincter  an incomplete band or thickening of the muscle fibers in the rectum a few inches above the anus in the upper part of the rectal ampulla.

tubal sphincter  an encircling band of muscle fibers at the junction of the uterine tube and the uterus.

vesical sphincter  internal sphincter muscle of urethra.

---

pyloric sphincter

n.

A thickening of the layer of the gastric musculature encircling the gastroduodenal junction. Also called sphincter muscle of pylorus.

---

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. Also called pyloric valve.