Linea alba (abdomen)

The linea alba (Latin for "white line") is a fibrous structure that runs vertically along the midline of the anterior abdominal wall. It is composed primarily of collagen and forms a raphe, or seam, created by the fusion of the aponeuroses of the abdominal muscles. Specifically, it is formed by the interlacing fibers of the aponeuroses of the external oblique, internal oblique, and transversus abdominis muscles from both the left and right sides of the abdomen.

The linea alba extends from the xiphoid process of the sternum to the pubic symphysis. Its width varies along its length, being wider superiorly and narrower inferiorly. It serves as an attachment point for these abdominal muscles, providing stability and support to the abdominal wall. Because it primarily consists of connective tissue and lacks significant blood supply, it is often used as a surgical entry point to minimize bleeding during abdominal procedures. The umbilicus (navel) is located along the linea alba, typically at approximately the L3-L4 vertebral level. Variations in the linea alba, such as diastasis recti (separation of the rectus abdominis muscles), can occur due to factors like pregnancy or obesity.