Final answer:
The spinothalamic tract pathway consists of three neurons that transmit sensory information to the brain.
Step-by-step explanation:
The spinothalamic tract pathway consists of three neurons. The first neuron starts in a dorsal root ganglion, and its axon extends to the dorsal horn where it synapses with the second neuron. The second neuron decussates within the spinal cord and ascends to the thalamus where it synapses with the third neuron. The axons from the third neurons project to the spinothalamic tract, which then synapses in the postcentral gyrus of the cerebral cortex.