Deep Inguinal Ring
The Transversalis Fascia is a firm membranous sheet lining the entire abdominopelvic cavity. It displays thickenings and outpouchings which display its independent character. It covers the internal surface of the transversus abdominis muscle and its aponeurosis. Below the linea semicircularis the transversalis fascia is the principal layer of the posterior sheath of the rectus abdominis muscle. The transversalis fascia lines the retroperitoneal aspect of the abdominopelvic cavity. It attaches and covers but is not limited to the following significant structures: the diaphragm, quadratus lumborum, psoas major, inferior vena cava, and obturator internus. The transversalis fascia is characteristically continued along blood vessels and other structures leaving the abdominopelvic cavity. It forms the Femoral Sheath. The principal outpouching of the transversalis fascia is the internal spermatic fascia; the mouth of this outpouching is the Deep Inguinal Ring. The posterior layer of the rectus sheath below the linea semicircularis is composed of transversalis fascia and peritoneum.