Final answer:
The somatic sensory signals are processed through a network that involves the spinal nerves, cranial nerves, and cerebral cortex, with the thalamus acting as a relay center for sensory data on its way to the cortex.
Step-by-step explanation:
The Role of the CNS in Somatic Sensory Signals
Spinal nerves, cranial nerves, and the cerebral cortex play crucial roles in the processing of somatic sensory signals within the central nervous system (CNS). Spinal nerves consist of mixed fibers, including sensory neurons that enter the spinal cord through the dorsal root and continue to the opposite hemisphere of the cerebral cortex for processing. Cranial nerves, on the other hand, can be purely sensory, like the olfactory, optic, and vestibulocochlear nerves, or mixed, like the trigeminal nerve, and are usually connected ipsilaterally. The spinal cord and brain stem form part of the ascending pathways that transmit sensory information from the body and head, respectively, to reach the diencephalon, specifically the thalamus, which is a critical relay station for sensory information on its way to the cerebral cortex.