Makeup of the Rectus Sheath at Different Levels

The rectus sheath consists of two lamina, the anterior sheath and the posterior sheath. The sheath is made up of the aponeuroses of the three anterolateral abdominal muscles (external abdominal oblique, internal abdominal oblique and the transversus abdominis) as they converge at the linea alba. The makeup of the anterior and posterior sheaths vary depending on the level of the abdominal wall you examine.

The three levels that we will examine are: