Endorphins: These are natural chemicals produced by the body that have similar effects to opioids. They are released during situations such as exercise or laughter and contribute to pain relief and feelings of pleasure.
Opioid Receptors: These are specific sites on nerve cells that interact with opioids like morphine. When opioids bind to these receptors, they block the transmission of pain signals and produce analgesic effects.
Tolerance: Tolerance refers to the diminishing response an individual has to a drug over time, requiring higher doses for the same effect. In the case of opioids, repeated use can lead to increased tolerance, reducing their effectiveness in providing pain relief.