Final answer:
The dorsal column system and spinothalamic tract are key ascending sensory pathways in the spinal cord, transmitting touch/proprioception and pain/temperature sensations respectively, with both pathways synapsing in the thalamus and somatosensory cortex.
Step-by-step explanation:
The two principal ascending sensory pathways in the spinal cord are the dorsal column system and the spinothalamic tract. The dorsal column system is specifically associated with conveying sensations of touch, vibration, and proprioception. It begins with neurons in the dorsal root ganglion, with the information ascending ipsilaterally and decussating at the medulla.
On the other hand, the spinothalamic tract is known for transmitting pain and temperature sensations. Its information enters the spinal cord, immediately decussates at the level of entry, and then ascends contralaterally. Despite their differences, both pathways involve a second neuron that crosses to the opposite side of the central nervous system and synapses in the thalamus, which sends projections to the somatosensory cortex.