Corpus: Lumbar arteries

The lumbar arteries are four paired branches of the abdominal aorta that supply blood to the wall of the abdominal trunk.

The lumbar arteries are a continuation of the posterior intercostal arteries. They typically consist of four pairs, emerging from the posterior aspect of the aorta at the level of the first four lumbar vertebrae.

Initially, the lumbar arteries run dorsally and laterally, passing behind the sympathetic trunk and through the spaces between the transverse processes of the lumbar vertebrae. On the right side, the arteries cross beneath the inferior vena cava, and the upper two lumbar arteries on each side also cross the corresponding crus of the diaphragm.

The arteries then continue along the posterior abdominal wall, arching behind the psoas major muscle and the lumbar plexus. Afterward, they pass the quadratus lumborum muscle, with the upper three lumbar arteries running behind this muscle and the fourth artery running in front. Laterally, they pierce the posterior aponeurosis of the transversus abdominis muscle and continue anteriorly between it and the obliquus internus abdominis muscle.

The lumbar arteries form anastomoses with the subcostal artery, the iliolumbar artery, the deep circumflex iliac artery, and the inferior epigastric artery.

• Posterior branch
• Spinal branches
• Muscular branches

The lumbar arteries, along with the accompanying lumbar vein, provide blood supply to the lumbar spine, the spinal canal, sections of the lumbar back muscles, and the lateral wall of the trunk.