The cauda equina, a Latin term meaning “horse’s tail,” is a bundle of nerve roots that extend from the bottom of the spinal cord. It is located below the level of the spinal cord termination, known as the conus medullaris. The conus medullaris typically ends at the L1 or L2 vertebra in the lumbar spine.
The cauda equina is composed of individual nerve roots that emerge from the spinal cord and continue to travel down within the spinal canal. These nerve roots branch out and extend towards various regions of the lower body. They include the lumbar, sacral, and coccygeal nerve roots.
Starting from the conus medullaris, the cauda equina contains nerve roots that correspond to the lower spinal levels. These nerve roots exit the spinal canal through small openings called intervertebral foramina. The cauda equina continues downwards and consists of nerve roots from the lumbar, sacral, and coccygeal regions.
Specifically, the cauda equina includes nerve roots from the level of L2 in the lumbar spine to the level of Co1 in the coccygeal spine. This means that the cauda equina encompasses the nerve roots of the lumbar and sacral plexuses, which are responsible for innervating various lower limb muscles, as well as providing sensation to the lower abdomen, hips, buttocks, genitals, and perineal region.
It is important to note that the exact termination point of the cauda equina can vary slightly among individuals. While most commonly the cauda equina ends at the level of Co1, it can occasionally extend a bit further or terminate slightly higher at the level of Co2. This slight anatomical variation does not significantly impact the overall function of the cauda equina.
The cauda equina is a group of nerve roots that extend from the conus medullaris, which is the end of the spinal cord. It includes nerve roots from L2 in the lumbar spine to Co1 in the coccygeal spine, branching out to innervate various regions of the lower body.