Schematic diagram of the anatomy of nociception and pain perception in the cat and dog. The pathway from registering noxious stimuli to perceiving pain involves multiple nociceptive tracts from various regions of the dorsal horn. Each tract transmits different sensory inputs to specific brain regions, contributing to the perception of pain based on a complex set of input. The spinocervicothalamic and spinothalamic tract are contributing to conscious pain perception, as they relay information to higher brain structures via the thalamus, whereas the spinoreticular and spinomesencephalic tract terminates in the brainstem and the reticular formation and plays a role in the descending modulatory system.