Rectus

Rectus abdominis muscle (commonly known as the "abdominal muscle") is a paired muscle running vertically on each side of the anterior wall of the human abdomen. There are two parallel muscles, separated by a midline band of connective tissue called the linea alba. It extends from the pubic symphysis, pubic crest and pubic tubercle inferiorly, to the xiphoid process and costal cartilages of ribs V to VII superiorly.

Structure

The rectus abdominis muscle is a long flat muscle, which extends along the whole length of the front of the abdomen, and is separated from its fellow of the opposite side by the linea alba.

Nerve supply

The rectus abdominis is innervated by thoracoabdominal nerves, the seven lower intercostal nerves.

Function

The rectus abdominis has several actions, the main one being to produce movement, such as flexing the spinal column, bringing the rib cage closer to the pelvis. It also helps in keeping the internal organs intact and in creating intra-abdominal pressure, such as when exercising or lifting heavy weights, during forceful defecation or parturition (childbirth).

Clinical significance

Injury to the rectus abdominis muscle or its nerve supply can cause a rectus sheath hematoma.

See also

• Abdominal exercise
• Pyramidalis muscle
• Transversus abdominis muscle