If a patient with chronic back pain experiences reduced pain sensitivity due to increased physical activity, which mechanism explains this phenomenon, involving descending modulation of nociceptor signals?

💡 Explanation

Descending modulation inhibits pain because endorphins are released during physical activity. These endorphins bind to receptors in the spinal cord, reducing the transmission of pain signals from nociceptors. Therefore, pain sensitivity decreases, rather than substance P increasing pain or gate control enhancing signal transmission.

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