Anterior Segmental Medullary Artery (Sacral; Right)

Origin

The segmental medullary, or radiculomedullary, arteries are described as feeder arteries that arise from the radicular arteries, particularly at the lower cervical, lower thoracic, and upper lumbar regions of the spinal cord (Standring, 2020). There are about 6-10 anterior segmental medullary arteries along the length of the spinal cord (Jones et al., 2013).

The largest segmental medullary artery is the great radicular artery (or great segmental medullary of Adamkiewicz), which variably arises from a spinal branch of the lower posterior intercostal arteries (T9-T11), the subcostal artery (T12), or from the upper lumbar arteries (L1 or L2) (Standring, 2020). It arises on the left side in 65% of individuals and is responsible for reinforcing arterial supply to the spinal cord (Moore, Dalley and Agur, 2013).

Course

The anterior segmental medullary artery follows the course of the anterior root of the spinal cord, medially, through the intervertebral foramina. It is large enough to reach the anterior spinal artery, which sits in the anterior median fissure of the spinal cord.

Branches

There are no named branches, however, the anterior segmental medullary artery divides into ascending and descending branches that anastomose with the anterior spinal artery.

Supplied Structures

The anterior segmental medullary artery supplies the anterior roots and rootlets of the spinal cord and the anterior two-thirds of the spinal cord.

List of Clinical Correlates

- Ischemic neurologic injury

References

Jones, H. R., Burns, T., Aminoff, M. J. and Pomeroy, S. (2013) The Netter Collection of Medical Illustrations: Nervous System, Volume 7, Part 1 - Brain e-Book. Elsevier Health Sciences.

Moore, K. L., Dalley, A. F. and Agur, A. M. R. (2013) Clinically Oriented Anatomy. Clinically Oriented Anatomy 7th edn.: Wolters Kluwer Health/Lippincott Williams & Wilkins.

Standring, S. (2020) Gray's Anatomy: The Anatomical Basis of Clinical Practice. 42nd edn.: Elsevier Health Sciences.