| MUS | any of four pairs of muscles extending from the cervical vertebrae to the second rib |
|---|---|
| MUS | muscles that rotate the scapula and elevate the rib cage |
| MUS | skeletal muscle that draws the rib cage backward and downward |
| MUS | the sphincter muscle of the anus |
| MUS | an external ring of striated muscle surrounding the anus |
| MUS | an internal ring of smooth muscle formed by circular fibers of the rectum |
| MUS | the smooth muscle sphincter of the common bile duct |
| MUS | the smooth muscle sphincter of the main pancreatic duct |
| MUS | a ring of smooth muscle surrounding the iris |
| MUS | the sphincter muscle of the pylorus that separates the stomach from the duodenum |
| MUS | a striated sphincter muscle that constricts the urethra |
| MUS | the sphincter muscle of the urinary bladder |