Answer
The pelvic diaphragm composed essentially of right and left levator ani muscles. The levator ani spreads across most f the pelvic outlet and forms the floor of the lesser (true) pelvis Compartments or muscles of the levator ani are the iliococcygeus, the ischiococcygeus and the pubococcygeus.
Actions of the levator ani:
a. compresses the anal canal
b. reinforces external anal and urethral sphincters
c. supports uterus and other and other pelvic viscera
d. aids in deep breathing
Work Step by Step
Origin of levator ani: Inner surface of lesser pelvis--pubis and spine of ischium
Insertion is on the coccyx through anococcygeal body; also on walls of urethra, vagina and anal canal.
Innervation is supplied by the pudendal nerve, and spinal nerves S2-S3.
