Functional neuroanatomy of pain.

Pain is an unpleasant but important biological signal for danger. Nociception is necessary for survival and for maintaining the integrity of the organism in a potentially hostile environment. Pain is induced by noxious stimuli that act on a complex pain sensory apparatus. However, chronic pain no longer affords a protective role, but can become a ruining disease itself, termed "neuropathic pain". This contribution throws light on the complex machinery of pain processing, from the perspective of the connections between key structures that are necessary for a profound understanding of the phenomenon of pain.