Perineum

(per-in-e'-um). That portion of the body included in the outlet of the pelvis, bounded in front by the pubic arch, behind by the coccyx and great sacro-sciatic ligaments, and at the sides by the tuberosities of the ischium. It includes all of the structures between the ischial tuberosities on either side, the anus posteriorly, and the vagina in the female and the scrotum in the male anteriorly. It is separated from the pelvic cavity by the recto-vesica i fascia. It is occupied by the terminations of the rectum, the urethra, and the root of the penis, together with their muscles, fasci?e, ve els, and nerves. In a more restricted sense, the term perineum is applied to the space in advance of the anus (true perineum); in the female it is occupied by the termination of the vagina, the vulva, and the clitoris. The median line of the perineum presents a slight ridge, the raphe.