Perineum

3D Model

The perineum is defined as the entire pelvic outlet. It is a roughly diamond shaped space formed be the pubis anteriorly, the ischial rami bilaterally, the ischial tuberosities and then posteriorly by the coccyx and bilaterally by the sacrotuberous ligaments. By drawing a line between the ischial tuerosities bilaterally, the perineum is subdivided into an anteirorly placed urogenital triangle and a posteriorly positioned anal triangle. The urogenital triangle is subdivided into a deep pouch that contains the urogenital diaphragm with its conspicuous inferior fasica called the perineal membrane and the superficial pouch including the erectile tissues and associated muscles as well as the urethra, glands, and lower portion of the vagina in the female.