The<unk>  is made up of 3 parts: * Iliococcygeus muscle * Pubococcygeus muscle * Puborectalis muscle The iliococcygeus arises from the inner side of the ischium (the lower and back part of the hip bone) and from the posterior part of the tendinous arch of the obturator fascia, and is attached to the coccyx and anococcygeal body; it is usually thin, and may be absent, or be largely replaced by fibrous tissue. An accessory slip at its posterior part is sometimes named the iliosacralis. The pubococcygeus muscle has medial fibres forming the pubovaginalis in the female, and the puboprostaticus in the male. Origin and insertion The<unk>  arises, in front, from the posterior surface of the superior pubic ramus lateral to the symphysis; behind, from the inner surface of the spine of the ischium; and between these two points, from the obturator fascia. Posteriorly, this fascial origin corresponds, more or less closely, with the tendinous arch of the pelvic fascia, but in front, the muscle arises from the fascia at a varying distance above the arch, in some cases reaching nearly as high as the canal for the obturator vessels and nerve. The fibers pass downward and backward to the middle line of the floor of the pelvis; the most posterior are inserted into the side of the last two segments of the coccyx; those placed more anteriorly unite with the muscle of the opposite side, in a median fibrous ridge called the anococcygeal body or raphe, which extends between the coccyx and the margin of the anus. The middle fibers are inserted into the side of the rectum, blending with the fibers of the sphincter muscles; lastly in the male, the anterior fibers descend upon the side of the prostate to unite beneath it with the muscle of the opposite side, joining with the fibers of the external anal sphincter and transverse perineal muscles, at the central tendinous point of the perineum. The anterior portion is occasionally separated from the rest of the muscle by connective tissue. From this circumstance, as well as from its peculiar relation with the prostate, which it supports as in a sling, it has been described as a distinct muscle, under the name of<unk>  prostatæ. In the female the anterior fibers of the<unk>  descend upon the side of the vagina. Innervation The<unk>  muscles are mostly innervated by the pudendal nerve, perineal nerve and acting together. Variation In addition, sacral spinal nerves (S3, S4) innervate the muscles directly as well (in ~70% of people). Sometimes (in ~40% of people) the inferior rectal nerve innervates the<unk>  muscles independently of the pudendal nerve.
Levator ani
Morcellator
Dilator
Superior oblique muscle
Inferior oblique muscle
Corpus cavernosum penis
Palatal obturator
Corpora quadrigemina