Where is it located and how is it formed?
The artery is formed by the union of two branches from the right and left vertebral arteries (a. vertebralis). Almost always, it originates from their intradural part.
Having merged into a single unpaired trunk, the artery descends longitudinally along the anterior surface of the spinal cord. It lies within the depression of the anterior median sulcus (fissure) — fissura mediana anterior, and extends throughout the entire length of the spinal cord down to the terminal filum (filum terminale).
What does it supply in the spinal cord?
The anterior spinal artery forms the anterior arterial territory. It nourishes the central and anterior parts of the spinal cord parenchyma. Its vascularization zone includes:
- Anterior horns.
- Central gray matter.
- Anterior spinothalamic tract.
- Lateral spinothalamic tract.
- Part of the pyramidal tract — including the lateral corticospinal tract.
- Deep regions of the anterior and lateral funiculi of the white matter.
Branches of the anterior spinal artery
Opposite each spinal cord segment, penetrating vessels depart from the main trunk:
- Sulcocommissural arteries (aa. sulcocommissurales) — transversely enter the median fissure, from where they penetrate the brain tissue. Each such artery strictly supplies one half of the segment's spinal cord parenchyma, providing nutrition to the ventral part of the gray matter.
Involvement in the blood supply to the brainstem
The anterior spinal artery, together with the paramedian branches of the vertebral artery, supplies the medial (paramedian) zone of the medulla oblongata. This zone includes:
- Pyramids.
- Medial lemniscus.
- Medial longitudinal fasciculus.
- Nuclei of the XII nerve.
Anastomoses and vascular features
The vascular pattern along the entire length of the spinal cord is not represented by isolated vessels, but by a long chain of anastomoses. The hyperemia of the anterior spinal artery is ensured by inflow from numerous segmental arteries; along its course, it anastomoses with the anterior radicular arteries.
- Artery of Adamkiewicz (a. radicularis magna) — the largest radicular artery, the main source of blood supply to the lower thoracic, lumbar, and sacral segments of the spinal cord.
During ontogeny, the spinal cord lengthens more slowly than the vertebral column (ascensus medullae spinalis). This creates a topographical discrepancy: the level of penetration of the radicular arteries is higher than the site of their origin from the aorta. Therefore, the radicular arteries have an oblique ascending course within the vertebral canal. The artery of Adamkiewicz empties into the anterior spinal artery at an acute angle, resembling an unbent hairpin in shape. Furthermore, the anterior and posterior main longitudinal vessels are interconnected via radicular anastomoses.
Clinical significance
The spinal cord, similarly to the brain, can be subject to ischemia of arterial or venous origin, as well as hemorrhages. The unpaired anterior spinal artery receives inflow from numerous segmental arteries.
Class and exam questions
Which vessels form the anterior spinal artery?
It is formed by the union of two branches of the right and left vertebral arteries; it almost always originates from their intradural part.
Which artery is an important source of blood supply to the lower parts of the spinal cord?
The great radicular artery, also known as the artery of Adamkiewicz. It is the main source of blood supply to the lower thoracic, lumbar, and sacral segments of the spinal cord and empties into the anterior spinal artery at an acute angle.
Which structures of the medulla oblongata are supplied with blood involving this artery?
The anterior spinal artery, together with the vertebral paramedian arteries, vascularizes the medial paramedian zone of the medulla oblongata: the pyramids, medial lemniscus, medial longitudinal fasciculus, and the nuclei of the XII nerve.
How do sulcocommissural arteries distribute blood in the spinal cord?
Each sulcocommissural artery, branching off from the anterior spinal artery, penetrates the brain tissue and strictly supplies one half of the parenchyma of its respective segment.
What else to study on this topic
- Vertebral artery (a. vertebralis)
- Artery of Adamkiewicz (a. radicularis magna)
- Posterior spinal arteries (aa. spinales posteriores)
- Blood supply to the medulla oblongata
Study the complete topic in the Anatomy course
This is a summary. The course covers everything tested in classes and exams.
- Complete study guide on "Anterior spinal artery" and 1,363 more pages of the subject
- Assignments and quizzes after every topic — just like in a colloquium
- AI tutor answers questions on the topic anytime
- 295 video lessons by subject
Other topics in the "Anatomical Structures" section
Free video lessons: AnatomyShort lessons with study notes — no registration required.
Prepared by WhiteCoat Pro faculty in accordance with the medical school curriculum. For educational purposes only.