Final answer:
The dorsal column-medial lemniscus pathway carries touch and proprioceptive information, decussating in the medulla, while the anterolateral pathway carries pain and temperature information, crossing over at the level it enters the spinal cord.
Step-by-step explanation:
Comparison of Dorsal Column-Medial Lemniscus Pathway and Anterolateral (Spinothalamic) Pathway
Both the dorsal column-medial lemniscus pathway and the anterolateral pathway, also known as the spinothalamic tract, are major sensory pathways originating from sensory neurons in the dorsal root ganglia and they carry different types of sensory information to the brain.
The dorsal column system primarily carries information about touch and proprioception and crosses the midline in the medulla. In contrast, the anterolateral pathway conveys primary sensory information about pain and temperature, and its fibers cross the midline at the level of the spinal cord where the sensory information enters.
The dorsal column system's sensory input ascends ipsilateral to the source of stimulus and decussates in the medulla, whereas the anterolateral pathway decussates at the point of entry into the spinal cord and then ascends contralaterally.
Both pathways involve three neurons, with the second neuron projecting contralaterally; in the dorsal column system, this occurs in the brain stem, while in the anterolateral pathway, this occurs in the spinal cord. The third neurons in both pathways synapse in the thalamus before projecting to the somatosensory cortex.
The segregation of these pathways allows for specific sensory deficits and their assessment, which serves to illustrate the differences in function between these two pathways.