Description: The perineum is a diamond-shaped region, folded as a kite between the pubic symphysis anteriorly, the ischial tuberosities laterally, and the coccyx posteriorly.  The triangle anterior to an imaginary line drawn between the tuberosities is the urogenital triangle,and posterior to the line is the anal triangle.The urogenital triangle is tilted superiorly parallel with the inferior rami of the pubic bones, and the anal part is inclined superiorly to the coccyx. Internal to the integument and external structures (vulva and anus), the pelvic diaphragm is comprised of ligaments and muscles, through which the apertures for the urethra, vagina, and anus emerge.  The perineal body is the central tendon of the perineum between the vulva and anus. The major muscles of  the pelvic diaphragm are the levator ani, and the coccygeous m.  The urogenital diaphragm, corresponding to the shape of, and lying superior to the urogenital triangle, and inferior to the levator sling, is comprised of two fascial leaves between which are the superficial transverse perineal m. Anteriorly, the bulbospongiosus m., and the internal urethral sphincter encircle the vagina and urethra, respectively, and the external anal sphincter does so posteriorly.  Antero-laterally, an inverted-V shaped m., the ischiocavernosis, extends along  the ramus of the pubis.