The perineum is the region between the thighs inferior to the pelvic diaphragm. The boundaries of this region are the same as that for the pelvic outlet, namely the pubic symphysis, ischiopubic rami, sacrotuberous ligaments, and coccyx. The perineum has a roof formed by the pelvic diaphragm and a floor of fascia and skin. It also contains the muscles and neurovasculature associated with urogenital structures and the anus.