The diagram shows manometric recordings from a patient before and after pelvic floor training. A balloon placed in the rectum was inflated (arrows) and deflated repeatedly. Tracing Z is a manometric recording obtained from the external anal sphincter before and after pelvic floor training. Which of the following best describe the origin of tracing X?

Question

Quizplus · Accepted Answer

Tracing X likely represents the pressure exerted by the internal anal sphincter. This is because the balloon was placed in the rectum, and tracing Z represents the external anal sphincter, which is closer to the opening of the anus. Tracing X being closer to the balloon inflation/deflation points suggests that it is measuring pressures within the rectum itself, which are likely originating from the internal anal sphincter.

The Diagram Shows Manometric Recordings from a Patient Before and After