Final answer:
Sensory pathways have common elements such as the dorsal column system and the spinothalamic tract, which transmit sensory information to the brain. Both pathways consist of three successive neurons, with the second neurons being contralateral. The thalamus and somatosensory cortex play important roles in processing sensory information.
Step-by-step explanation:
All sensory pathways have some common elements. There are two major ascending pathways in the central nervous system: the dorsal column system and the spinothalamic tract. These pathways bring sensory information to the brain. The dorsal column system is responsible for touch sensations and proprioception, while the spinothalamic tract pathway is responsible for pain and temperature sensations. The sensory pathways in both systems consist of three successive neurons. The second neurons in both pathways are contralateral, meaning they project across the midline to the other side of the brain or spinal cord. In both systems, the second neuron synapses in the thalamus, and the thalamic neuron projects to the somatosensory cortex. These common elements allow for the transmission of sensory information to the appropriate areas of the brain for processing and perception.