Final answer:
The nucleus cuneatus and nucleus gracilis are located in the caudal medulla. They are crucial for processing sensory information from the body and relay this information to the thalamus and cerebral cortex.
Step-by-step explanation:
The nucleus cuneatus and nucleus gracilis are part of the sensory pathways in the central nervous system. These nuclei are located in the caudal medulla, which is at the lower part of the brainstem just above the spinal cord. The axons within the dorsal column of the spinal cord terminate in these medullary nuclei, where they synapse with the second neurons in their pathway.
The nucleus gracilis receives input from the fasciculus gracilis, carrying sensory information from the lower body and legs, while the nucleus cuneatus is the target for the fasciculus cuneatus, carrying information from the upper body and arms. After synapsing in these nuclei, the second-order neurons decussate and ascend as the medial lemniscus to the thalamus, before projecting to the cerebral cortex.