Question

external anatomy of the spinal cord
the bundle of nerves inferior to the conus medullaris of the spinal cord is called what?
lumbar enlargement
cervical enlargement
posterior median sulcus
cauda equina

Explanation:

The conus medullaris is the tapered end of the spinal cord. Inferior to it, the bundle of nerves resembles a horse's tail. The term "cauda equina" literally means "horse's tail" in Latin. The lumbar enlargement and cervical enlargement are regions where the spinal cord is thicker (due to more neurons for innervating limbs). The posterior median sulcus is a groove on the posterior (dorsal) side of the spinal cord.

Answer:

Cauda equina