Rectus sheath

Rectus Sheath

The Rectus Sheath (pronounced: REK-tus sheeth) is a complex structure in the anatomy of the abdomen. It is formed by the aponeuroses of the abdominal muscles and encloses the rectus abdominis muscles.

Etymology

The term "Rectus Sheath" is derived from the Latin words "rectus" meaning straight, and "sheath", which is a cover. This is in reference to the sheath-like structure that covers the straight abdominal muscles.

Structure

The Rectus Sheath is composed of the aponeuroses of three muscles: the external oblique, the internal oblique, and the transversus abdominis. These aponeuroses form a strong, fibrous compartment that encloses the rectus abdominis muscles and the pyramidalis.

Function

The primary function of the Rectus Sheath is to protect and maintain the position of the rectus abdominis muscles. These muscles are crucial for maintaining posture and facilitating movement, particularly in the trunk region. The sheath also allows for the passage of the superior and inferior epigastric vessels.

Related Terms

Linea Alba: A fibrous structure that runs down the midline of the abdomen, formed by the fusion of the aponeuroses of the abdominal muscles.
Arcuate Line: A horizontal line that demarcates the lower limit of the posterior layer of the rectus sheath.
Semilunar Line: A curved line on the abdominal wall that marks the lateral border of the rectus sheath.