Final answer:
In the spinal cord, sensory neurons are associated with the dorsal horn, and motor neurons are associated with the ventral horn. Both dorsal and ventral roots are part of the spinal nerves, involved in transmitting sensory and motor information, respectively. This structure results from the differentiation of embryonic neural tube tissues.
Step-by-step explanation:
In the vertebrate spinal cord, the dorsal horn is associated with sensory neurons, and the ventral horn is associated with motor neurons.
The nerves connected to the spinal cord are the spinal nerves, possessing combined sensory and motor axons. Each spinal nerve separates into dorsal and ventral nerve roots as it nears the spinal cord. The dorsal root contains only the axons of sensory neurons, gathered in the dorsal root ganglia, and they enter the dorsal spinal cord. Conversely, the motor fibers exit the spinal cord through the ventral root, with neuronal cell bodies located within the ventral gray matter.
During embryonic development, the spinal cord forms from the neural tube, with dorsal tissues becoming associated with sensory functions and ventral tissues with motor functions. The posterior or dorsal horns of the gray matter are devoted to sensory functions, whereas the anterior or ventral horns are involved in motor functions.