Notes
Spinal Cord Arteries
ANTERIOR SPINAL ARTERY
- Vertebral artery branches join to form the anterior spinal artery, which descends the anterior median fissure and supplies the anterior two-thirds of the spinal cord.
POSTERIOR SPINAL ARTERIES
- Each vertebral artery produces a single posterior spinal artery that descends the posterior spinal cord and supplies the posterior one-third of the spinal cord.
Note that often the posterior spinal arteries originate from the posterior inferior cerebellar arteries (PICAs).
Also, note that posteromedial spinal arteries can also exist.
CERVICAL SPINAL CORD
- Source artery - subclavian artery.
- Upper cervical spinal cord segmental arteries - Spinal segmental branches of the vertebral arteries.
- Lower cervical spinal cord segmental arteries - Ascending cervical artery (from the thyrocervical trunk) and the deep cervical artery (from the costocervical trunk).
THORACIC AND LUMBAR SPINAL CORD
- Source artery - Descending aorta.
- Thoracic cord segmental arteries - Posterior intercostal arteries.
- Lumbar cord segmental arteries - Lumbar arteries.
SACRAL SPINAL CORD
- Source artery - Internal iliac artery.
- Segmental arteries - Lateral sacral arteries.
SPINAL CORD ARTERIAL TREE
- Source artery -> Segmental artery -> Ventral and dorsal branches; the dorsal branch is called the dorsospinal artery -> Forms three types of radicular arteries:
- Radicular arteries (proper) (anterior and posterior) supply the nerve roots
- Radiculomedullary arteries supply the anterior spinal artery
- Radiculopial arteries supply the posterior spinal arteries and the pial network
PIAL NETWORK
- A ring of arterial supply that surrounds the spinal cord.
- It has superior-inferior interconnections that form an arterial meshwork around the cord.
ARTERY OF ADAMKIEWICZ:
* The most important radiculomedullary artery.
- Arises from T9 to T12, most commonly, but can originate anywhere from T8 to L3.
- It most commonly originates from the left side.
- Injury to this artery can lead to paraplegia.
ARTERY OF THE CERVICAL ENLARGEMENT:
- Another notable radiculomedullary artery at the C5 to C7 level.
INTRINSIC ARTERIAL TERRITORIES
Centrifugal and centripetal systems.
CENTRIFUGAL SYSTEM:
Comprises sulcal arteries from the anterior spinal artery, which supply the spinal cord from central to peripheral - primarily supply the gray matter horns.
CENTRIPETAL SYSTEM:
Comprises vasocoronal perforating arteries from the pial arterial network, which supply the spinal cord from peripheral to central - primarily supply the white matter funiculi.
VENOUS ANASTOMOSES
Communicate with surrounding venous plexuses.