This muscle must be consciously relaxed during defecation in order to decrease the bend of the anorectal junction and permit easy passage of feces through the rectum.
A)Iliococcygeus
B)External anal sphincter
C)Coccygeus
D)Pubococcygeus
E)Puborectalis

Question

Quizplus · Accepted Answer

The puborectalis muscle is part of the levator ani muscle group and forms a sling-like structure around the anorectal junction. Contraction of this muscle can cause the anorectal angle to increase, creating a "kink" that can impede fecal passage. Therefore, during defecation, the puborectalis muscle must be consciously relaxed in order to decrease the angle and allow for easy passage of feces through the rectum.

This Muscle Must Be Consciously Relaxed During Defecation in Order