Conus medullaris

Conus medullaris
Cauda equina and filum terminale seen from behind. The dura mater has been opened and spread out, and the arachnoid mater has been remove

The conus medullaris is the terminal end of the spinal cord. It occurs near lumbar nerves 1 (L1) and 2 (L2). After the spinal cord terminates, the spinal nerves continue as dangling NERVE ROOTS (not nerves as nerves are part of the PNS) called the cauda equina. The upper end of the conus medullaris is usually not well defined.

Blood supply

The blood supply consists of three spinal arterial vessels—the anterior median longitudinal arterial trunk and two posterolateral trunks. Other less prominent sources of blood supply include radicular arterial branches from the aorta, lateral sacral arteries, and the fifth lumbar, iliolumbar, and middle sacral arteries. The latter contribute more to the vascular supply of the cauda equina.

Pathology

Conus medullaris syndrome is a collection of signs and symptoms associated with injury to the conus medullaris.