Muscle
Rectus abdominis
Paired vertical muscles inside the rectus sheath
High-yield
Its arterial supply approaches from both ends: superior and inferior epigastric vessels meet within the rectus sheath.
Overview
Rectus abdominis runs from the pubis toward the lower anterior chest on each side of the linea alba. Tendinous intersections divide its visible surface into segments, but the muscle acts across the trunk to assist flexion and abdominal compression.
Reference facts
- Origin
- Pubic crest and the region of the pubic symphysis.
- Insertion
- The xiphoid process and costal cartilages of ribs 5–7.
- Action
- Flexes the lumbar trunk, supports pelvic position and compresses the abdominal viscera.
- Innervation
- Anterior rami T7–T12, through thoracoabdominal and subcostal nerves.
- Blood supply
- Superior and inferior epigastric arteries form its principal longitudinal supply.
Clinical correlation
Bleeding from rectus muscle or its epigastric vessels can collect in the sheath and produce abdominal pain. The pattern of spread depends partly on the sheath's changing structure below the arcuate line.
Frequently asked questions
What does the rectus abdominis do?
The rectus abdominis flexes the lumbar trunk, supports pelvic position and compresses the abdominal viscera.
What nerve innervates the rectus abdominis?
Anterior rami T7–T12, through thoracoabdominal and subcostal nerves.
Where does the rectus abdominis attach?
Origin: Pubic crest and the region of the pubic symphysis. Insertion: The xiphoid process and costal cartilages of ribs 5–7.
What is the blood supply of the rectus abdominis?
Superior and inferior epigastric arteries form its principal longitudinal supply.