- Four in number (L1-L4)
- Leave the Abdominal Aorta opposite the bodies of the upper four vertebrae
- Pass behind the Lumbar Sympathetic Trunks and Fibrous arches in the Psoas
- On the right:
- Upper two Lumbar Arteries posterior to Right Crus of the Diaphragm
- Lower two Lumbar Arteries posterior to the Inferior Vena Cava
- On the left:
- Uppermost Lumbar Artery posterior to the Left Crus of the Diaphragm
- Each gives off posterior and spinal branches
- Pass laterally behind Psoas muscle
- Three upper arteries pass laterally behind Quadratus Lumborum into the neurovascular plane between Transversus Abdominis and Internal Oblique
- Fourth Lumbar Artery – passes across to the neurovascular plane in front of the Quadratus Lumborum, along the upper margin of the Iliolumbar Ligament
- No Fifth Lumbar Arteries
- Its place is taken by the Lumbar branch of the Iliolumbar Artery (a branch of the Internal Iliac Artery)
- Ascends from the Pelvis in front of the Lumbosacral Trunk
- Passes laterally behind the Obturator Nerve and Psoas Muscle
- Supplies Psoas and Quadratus Lumborum
- Gives a spinal branch which enters the L5-S1 intervertebral foramen
- Iliac Branch runs in the Iliac Fossa, supplying Iliacus and the Ilium
- Ends in the anastomosis at the ASIS
Source: NETTER ATLAS 8th