internal sphincter muscle of anus


A smooth muscle ring formed by an increase of the circular fibers of the rectum, situated at the upper end of the anal canal.

Nearby words

  1. internal revenue,
  2. internal revenue service,
  3. internal rhyme,
  4. internal secretion,
  5. internal spermatic artery,
  6. internal stress,
  7. internal thoracic vein,
  8. internal traction,
  9. internal urethral opening,
  10. internal version

The American Heritage® Stedman's Medical Dictionary Copyright © 2002, 2001, 1995 by Houghton Mifflin Company. Published by Houghton Mifflin Company.