Lumbar arteries

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Lumbar arteries are a group of arteries that arise from the abdominal aorta and supply blood to the lumbar vertebrae, the muscles of the lower back, and the spinal cord. There are typically four pairs of lumbar arteries, although the number can vary.

Anatomy

The lumbar arteries originate from the posterior aspect of the abdominal aorta. They are usually four in number on each side, but there can be variations with some individuals having five pairs. These arteries are named the first through fourth lumbar arteries, corresponding to the vertebral levels from which they arise.

Course

Each lumbar artery passes laterally and posteriorly over the bodies of the lumbar vertebrae. They travel behind the psoas major muscle and the quadratus lumborum muscle. The arteries then divide into dorsal and spinal branches.

Dorsal Branches

The dorsal branches supply the muscles and skin of the back. They also give off smaller branches that anastomose with the intercostal arteries and the iliolumbar artery.

Spinal Branches

The spinal branches enter the intervertebral foramina to supply the vertebrae, the spinal meninges, and the spinal cord. These branches contribute to the anastomosis around the spinal cord, ensuring a rich blood supply.

Function

The primary function of the lumbar arteries is to provide oxygenated blood to the structures of the lower back, including the lumbar vertebrae, the muscles of the lower back, and the spinal cord. This blood supply is crucial for the nourishment and proper functioning of these structures.

Clinical Significance

The lumbar arteries can be involved in various medical conditions. For instance, they can be a source of bleeding in cases of trauma to the lower back. They may also be involved in the formation of aortic aneurysms or other vascular diseases. In surgical procedures involving the lumbar spine, care must be taken to avoid damaging these arteries to prevent excessive bleeding and ensure adequate blood supply to the spinal cord and surrounding structures.

See Also

• Abdominal aorta
• Intercostal arteries
• Iliolumbar artery
• Spinal cord
• Lumbar vertebrae