Linea

Linea simplex

Linea alba (Latin for "white line") is a fibrous structure that runs down the midline of the abdomen in humans and other vertebrates. The linea alba is an important anatomical landmark that separates the left and right halves of the abdominal muscles, specifically the rectus abdominis muscles. It extends from the xiphoid process of the sternum to the pubic symphysis, forming the anterior wall of the abdominal cavity.

Structure

The linea alba is formed by the interlacing fibers of the tendons of the abdominal muscles, including the external oblique, internal oblique, and transversus abdominis. This fibrous band is composed mostly of collagen, making it both tough and flexible. It varies in width and thickness among individuals and can become more pronounced during certain conditions, such as pregnancy.

Function

The primary function of the linea alba is to provide a structure for the attachment of the abdominal muscles, facilitating the movement and support of the trunk. It also serves as a site for surgical incisions, as cutting along the linea alba can minimize damage to muscle tissue and reduce post-operative recovery time. This is commonly performed during procedures such as cesarean sections and laparotomies.

Clinical Significance

1. 1. 1. Diastasis Recti

A condition associated with the linea alba is diastasis recti, which occurs when there is a separation of the rectus abdominis muscles along the linea alba. This condition is most commonly seen in pregnant women due to the increased tension on the abdominal wall but can also occur in men and non-pregnant women.

1. 1. 1. Hernias

Hernias can also occur along the linea alba, known as ventral or epigastric hernias, due to a weakness or opening in the fibrous band. This allows abdominal contents to protrude, creating a bulge visible on the surface of the abdomen.

Surgical Importance

The linea alba is a preferred site for abdominal incisions by surgeons due to its avascular nature, which reduces the risk of bleeding during surgery. Additionally, incisions along the linea alba can heal with less scarring and have a lower risk of infection.

See Also

• Abdominal wall
• Rectus sheath
• Abdominal surgery