Question

In terms of vertebral levels, where are the nerve roots of the spinal cord typically located?

a) Below corresponding vertebrae
b) Above corresponding vertebrae
c) At the same level as vertebrae
d) In the intervertebral discs

Answer 1

a) Below corresponding vertebrae

The nerve roots of the spinal cord are typically located below corresponding vertebrae, with spinal nerves emerging from the intervertebral foramen at their respective levels and forming the cauda equina for lower spinal segments.

Step-by-step explanation:

In terms of vertebral levels, the nerve roots of the spinal cord are typically located below corresponding vertebrae. There are 31 spinal nerves, with each nerve emerging from the vertebral column through the intervertebral foramen at its level. The cervical nerves, designated C1 to C8, emerge from above their corresponding vertebrae except for C8, which emerges between the seventh cervical vertebra and the first thoracic vertebra. However, starting from the thoracic nerves, each subsequent spinal nerve emerges below its corresponding vertebra (T1 between T1 and T2, T2 between T2 and T3, and so on). This arrangement is due to how the spinal cord and the vertebral column grow at different rates, with the spinal cord not growing significantly longer after the first or second year, while the skeleton continues to grow. As a result, lower spinal nerves travel for a longer distance within the spinal canal before exiting, forming a long bundle of nerves known as the cauda equina.