Final answer:
The neuronal cell bodies of the dorsal roots of spinal nerves are found in the dorsal root ganglia, which relay sensory information to the spinal cord.
Step-by-step explanation:
The neuronal cell bodies of the dorsal roots of spinal nerves are located in the dorsal root ganglia. These ganglia provide a critical interface between the peripheral and central nervous system, containing the cell bodies of sensory neurons that relay information from sensory receptors in the body to the spinal cord. This distinct structure is identifiable under the microscope as an enlargement of the nerve root, housing unipolar neurons and their axons. The satellite glial cells can also be found in this location, which play a supportive role for the neurons. In contrast, the somas of motor neurons reside within the ventral horn of the spinal cord's gray matter, delivering commands to muscles through the ventral roots.