Phenomenon of referred pain
A very likely explanation for the phenomenon of referred pain relates to the convergence of visceral and somatic afferent input to wide dynamic range neurons of lamina V. As a result of the convergence, injury-induce increased activity of visceral afferent nociceptors is interpreted by the brain as having arisen from the source of the convergent somatic input. It is thus “referred” to the somatic site. Indeed, local anesthetic injection of the site of reference can reduce referred pain even though the site of injury is clearly in the viscera.
