Mo was running a marathon when he tripped and fell. Even though he was bleeding, and he would have a number of bruises later, he was able to finish the race without experiencing much pain. Which of the following chemicals is most likely to be responsible for his reduced experience of pain?

Question

Quizplus · Accepted Answer

Endorphins are chemicals released by the body that function as natural painkillers. They bind to opioid receptors in the brain and spinal cord, reducing the experience of pain. Exercise, such as running a marathon, is known to stimulate the release of endorphins in the body, which may explain why Mo was able to finish the race without much pain despite his injuries.

Mo Was Running a Marathon When He Tripped and Fell