Final answer:
The dorsal column system and the spinothalamic tract are two major somatosensory pathways. The dorsal column system is responsible for touch and proprioception, while the spinothalamic tract is responsible for pain and temperature sensations.
Step-by-step explanation:
The two major somatosensory pathways are the dorsal column system and the spinothalamic tract. The dorsal column system primarily carries touch sensations and proprioception, while the spinothalamic tract is responsible for pain and temperature sensations. Both pathways consist of three successive neurons, with the second neuron in each pathway crossing to the opposite side of the brain or spinal cord. The third neuron in both pathways synapses in the thalamus and projects to the somatosensory cortex.