Nociceptors in skeletal muscle and their reaction to pathological tissue changes

A nociceptor has been defined as a receptive ending that is activated by noxious (tissue threatening, subjectively painful) stimuli, is capable by its response behaviour of distinguishing between innocuous and noxious events, and encodes the intensity of noxious stimuli. When tested with graded natural stimuli (mechanical, chemical, thermal), these receptors do not respond to stimuli such as that which occurs during the normal activity of the muscle but rather it requires noxious intensities of stimulation for activation. A liminal activation of a muscle nociceptor may occur if the intensity of stimulation approaches noxious levels without damaging the tissue. Teleologically, this property is important, since a nociceptor is supposed not only to signal tissue damage but also to prevent its occurrence.