 The deep transverse perineal muscle is innervated by the pudendal nerve.The function of the muscle is fixation of the perineal body (central tendon of perineum), support of the pelvic floor, expulsion of semen in males and last drops of urine in both sexes.The deep transverse perineal muscle lies in the same plane as the urethral sphincter and formerly the two muscles were described together as the constrictor urethrae.