The fifth lumbar dorsal root ganglia are swellings located on the fifth lumbar dorsal roots, proximal to where the dorsal roots join with the fifth lumbar ventral roots.  They are situated in the intervertebral foramina between the pedicles of L5 and S1, immediately lateral to the perforation of the dura by the dorsal root.

The dorsal root ganglia are formed by the cell bodies of somatic and visceral afferent neurons.  Each neuron has a single short axon, which divides into a medial branch, which enters the spinal cord via the dorsal root, and a lateral branch, which passes peripherally to a sensory end organ.