Final answer:
Endogenous opioids such as endorphins, enkephalins, and dynorphins play a role in modulating pain pathways in the body by binding to opioid receptors and inhibiting pain signals. They are released in response to tissue damage or inflammation and can contribute to the positive effects of exercise on pain perception.
Step-by-step explanation:
Endogenous opioids such as endorphins, enkephalins, and dynorphins are involved in the modulation of pain pathways in the body.
When there is tissue damage or inflammation, these endogenous opioids are released and bind to opioid receptors on nerve cells in the spinal cord and brain. This binding inhibits the conduction of pain signals, thereby reducing pain perception. For example, when you engage in vigorous aerobic exercise, the body releases endorphins, which are a type of endogenous opioids. The release of endorphins can contribute to the phenomenon known as a "runner's high" and help decrease pain sensitivity.