Final answer:
Endorphins are painkilling chemicals that occur naturally in the body. They are produced in response to stress, pain, and exercise and bind to opioid receptors to reduce pain and promote well-being.
Step-by-step explanation:
Endorphins are the painkilling chemicals that occur naturally in the body. They are produced by the central nervous system and pituitary gland in response to stress, pain, and exercise. Endorphins bind to opioid receptors in the brain and spinal cord, reducing the perception of pain and promoting a sense of well-being.
Learn more about Painkilling chemicals in the body