Vessels and nerves of the vertebral column

Definitions & Key takeaways

The vertebral column is supplied by a complex network of vessels and nerves. Its arterial supply comes from multiple sources, including the periosteal, equatorial, and spinal branches of major cervical arteries like the vertebral, ascending cervical, and deep cervical arteries. Additionally, segmental arteries like the intercostal, lumbar, and sacral arteries also contribute to the arterial supply of the vertebral column. Venous blood drains into the internal and external vertebral venous plexuses. The majority of the vertebral column is innervated by the recurrent meningeal nerves, except the facet joints, which are innervated by the articular branches of the medial branches of the posterior rami of spinal nerves.

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The vertebral column is important for protecting the spinal cord, as well as providing structural support, flexibility, and range of motion to our bodies.
To maintain all of these important functions, our vertebral column requires an adequate blood supply and innervation. Alright, let’s start with the arteries of the vertebrae, which arise from various larger, parent arteries depending on the level of the vertebral column.
In the neck, parent arteries include the vertebral and ascending cervical arteries; In the thorax, the posterior intercostal arteries; In the abdomen, they include the subcostal and lumbar arteries.
And finally, in the pelvis, parent arteries include the iliolumbar, lateral sacral, and median sacral arteries. Now, as these parent arteries cross the external surfaces of the vertebrae, they give rise to periosteal, equatorial, and spinal branches that directly supply the vertebrae.
Periosteal branches supply the periosteum, which is a dense layer of connective tissue that surrounds the vertebrae. The equatorial branches supply the vertebral bodies themselves.
Spinal branches pass through the intervertebral foramina and divide into smaller anterior and posterior vertebral canal branches.
Anterior vertebral canal branches follow the surface of the vertebral body anteriorly within the vertebral canal. Here, these arteries send nutrient branches that supply the red marrow of the vertebral body.
Posterior vertebral canal branches follow the vertebral arch posteriorly within the vertebral canal. These branches terminate as radicular arteries that supply the nerve roots, and segmental medullary arteries that supply the spinal cord.
Finally, both of these branches give rise to ascending,and descending branches that anastomose with spinal canal branches of adjacent levels.Venous blood drains from the vertebral column through spinal, basivertebral, and intervertebral veins.
Let’s start with spinal veins, which form plexuses along the vertebral column. These plexuses include the internal vertebral or epidural venous plexuses, which lie inside the vertebral canal, or the external vertebral venous plexuses, outside the vertebral canal.
These plexuses communicate through the intervertebral foramina. Now, the internal vertebral venous plexuses are further divided into the anterior internal vertebral venous plexus, lying more anteriorly in the vertebral canal, and the posterior internal vertebral venous plexus, lying more posteriorly.
Additionally, the internal vertebral plexus may form large longitudinal sinuses. The external vertebral venous plexuses are divided similarly, with the anterior external vertebral venous plexus lying just anterior to the vertebral bodies, and the posterior external vertebral venous plexus lying posterior to the spinous processes.Next are the large basivertebral veins, which drain the vertebral bodies.
These veins emerge from the small foramina on the surfaces of the vertebral bodies, and drain into both the anterior internal, and anterior external vertebral venous plexuses.
Finally, the intervertebral veins. These veins receive venous blood from the spinal cord and vertebral venous plexuses.
Then, taking the same path as the spinal nerves, they exit the spinal canal through the intervertebral foramina draining into the vertebral veins of the neck and the segmental veins of the trunk.Now let’s talk about nerves!
The entire vertebral column is innervated by meningeal or recurrent meningeal nerve branches that arise from mixed spinal nerves as they exit the intervertebral foramen.
The only exception to this are the facet joints. Facet joints are innervated by articular branches, which arise from the medial branches of the posterior rami of spinal nerves.
The meningeal branches, which run on each side of all vertebrae are special because they are the only nerves to arise from mixed spinal nerves, before they split into the anterior and posterior rami.
Most of these branches run back through the intervertebral foramen and into the vertebral canal, which explains why they are also known as the recurrent meningeal nerves, while other branches remain outside the vertebral canal.
Branches that enter the canal branch off and distribute fibers to the periosteum, ligamenta flava, the posterior longitudinal ligament, spinal dura mater, blood vessels and the posterolateral aspects of the anulus fibrosus of the intervertebral discs.
Branches that remain outside the canal innervate the anterolateral aspects of the vertebral bodies and their covering periosteum, the anulus fibrosus of the intervertebral discs, as well as the anterior longitudinal ligament.All right, as a quick recap, the vertebral column’s arterial supply comes from periosteal, equatorial and spinal branches of the major cervical and segmental arteries.
Venous blood drains into the internal and external vertebral venous plexuses. The majority of the vertebral column is innervated by the recurrent meningeal nerves, with the exception of the facet joints, which are innervated by the articular branches of the medial branches of the posterior rami of spinal nerves.