Continence course quizzes - Study guides, Class notes & Summaries

The internal anal sphincter is: a. A continuation of the longitudinal muscles. b. Stimulated to contract by rectal filling. c. Reflexively relaxes by rectal filling. d. Under volitional control - Answer-c. Reflexively relaxes by rectal filling. The internal sphincter is tonically contracted at all times to prevent leakage...until the rectum fills, then it automatically relaxes to allow contents to move into contact with the epithelium lining the transition zone so it can detect gas, ...