Urogenital diaphragm is the triangular musculo-fascial diaphragm that is present in the anterior part of the perineum. It is formed by the sphincter urethrae and deep transverse perineal muscles and fills the gap of the pubic arch. The muscles forming the urogenital diaphragm are enclosed between a superior and an inferior layer of fascia. The inferior layer is commonly known as the perineal membrane.
The two layers of fascia covering the urogenital diaphragm fuse anteriorly, leaving a small gap beneath the symphysis pubis. Posteriorly, the two layers of the fascia fuse with each other and with the membranous layer of the superficial fascia and perineal body. Towards the lateral sides, both layers of fascia are attached to the pubic arch.
The closed space contained between the superficial and deep layers of fascia, towards the lateral side, is known as deep perineal pouch.