The perineal membrane is a thin triangular horizontal layer of dense tough fascia in the perineum which divides the urogenital triangle into superficial (inferior) and deep (superior) perineal pouches.
It attaches to the inferior margins of the ischiopubic rami, enclosing the anterior portion of the pelvic outlet. Its posterior margin is thickened and connects to the transverse perineal ligament which contains the perineal body in the midline, a condensation of fibromuscular tissue with various muscular attachments.
In both sexes, the perineal membrane provides tough support to the genital organs that traverse it or directly attach to it. The ischiocavernosus attaches to the lateral margin and the bulbospongiosus attaches to the medial aspect of the membrane's inferior surface.