Final answer:
The spinothalamic tract follows the pain pathway through three neurons, decussating in the spinal cord and including the thalamus as a key relay station en route to the somatosensory cortex in the brain for processing pain and temperature sensations.
Step-by-step explanation:
The spinothalamic tract is responsible for transmitting pain and temperature sensations from the periphery to the brain, utilizing a pathway that includes three neurons. This tract decussates (crosses over to the opposite side) in the spinal cord at the level it enters. The initial neuron begins in a dorsal root ganglion and synapses with the second neuron in the spinal cord, which then projects axons across the midline within the spinal cord. The second neuron ascends to the third neuron in the thalamus, and from there, the information is relayed to the somatosensory cortex in the brain, allowing for pain perception.
Comparatively, the dorsal column-medial lemniscus pathway carries information regarding touch and proprioception, crossing over in the brainstem at the level of the medulla. These two pathways, while conveying different types of sensory information, both involve three successive neurons and share the thalamus as a relay station before reaching the somatosensory cortex.