rectus abdominis muscle
- origin: pubic symphysis, tubercle and crest
- insertion: xiphisternum and 5-7costal cartilages
- action: supports abdominal viscera, compression of the abdomen, trunk movement
- blood supply: superior and inferior epigastric arteries
- innervation: anterior rami of T6-L1 spinal nerves
The rectus abdominis has three-to-four horizontal tendinous intersections that divide the muscle into segments, which are often incomplete posteriorly. It is divided into two halves by the vertical linea alba. Laterally, the rectus sheath fuses to form the linea semilunaris.