Levator ani

Thin, sheet-like muscles that support the pelvic viscera.  From medial to lateral they are the puborectalis, pubococcygeus, and iliococcygeus.  Both left and right puborectalis mm. attach to the pubis and meet in the midline posterior to the rectum to form a sling around the rectum.  The left and right pubococcygeus attach anteriorly to the pubis and posteriorly to the coccyx.  The left and right iliococcygeus attach anteriorly to the thickened fascia of the obturator internus mm., and posteriorly to the coccyx.  The levator ani are innervated by the pudendal n.