Organ
Spinal cord
Central pathway and local processing center within the spine
High-yield
The adult cord usually ends near L1–L2, while the fluid-filled meningeal sac continues farther down. Spinal cord segment numbers and vertebral numbers describe different levels and increasingly diverge lower in the spine.
Overview
The spinal cord connects the brainstem with spinal nerves and contains circuits for movement, sensation and autonomic control. Gray matter forms a central butterfly-shaped core; surrounding white matter carries ascending and descending signals. Enlargements serve the upper and lower limbs.
Reference facts
- Location
- Inside the vertebral canal, continuous with the medulla at the foramen magnum and tapering into the conus in the upper lumbar region in most adults
- Parts
- Cervical and lumbosacral enlargements and a terminal conus; 31 segments associated with 8 cervical, 12 thoracic, 5 lumbar, 5 sacral and 1 coccygeal nerve pairs
- Blood supply
- A longitudinal anterior spinal artery and paired posterior spinal arteries, supported by segmental feeders and connecting vessels; their territories overlap
- Relations
- Closely covered by pia and surrounded by subarachnoid fluid, arachnoid and dura; pial attachments help support it, with the epidural space outside the dural sac
- Function
- Carries signals between body and brain and integrates spinal reflexes, motor activity and autonomic responses
Mnemonic
Cord before sac: the cord usually ends near L1–L2; the sac continues toward S2.
Clinical correlation
A vertebral injury may affect cord segments with different numbers, or lower nerve roots where the cord has already ended. The neurological consequences depend on the actual structures and extent of injury, not simply the vertebral label.
Frequently asked questions
Where is the spinal cord located?
Inside the vertebral canal, continuous with the medulla at the foramen magnum and tapering into the conus in the upper lumbar region in most adults.
What does the spinal cord do?
Carries signals between body and brain and integrates spinal reflexes, motor activity and autonomic responses.
What are the parts of the spinal cord?
Cervical and lumbosacral enlargements and a terminal conus; 31 segments associated with 8 cervical, 12 thoracic, 5 lumbar, 5 sacral and 1 coccygeal nerve pairs.
What is the blood supply of the spinal cord?
A longitudinal anterior spinal artery and paired posterior spinal arteries, supported by segmental feeders and connecting vessels; their territories overlap.