Analgesics: These are medicines designed to relieve pain. They're like different types of keys designed to lock away different kinds and levels of pain.
Opioid Receptors: These are protein molecules located on nerve cells where opioids bind. They're like the specific locks designed for opiate "keys".
Endorphins:These are chemicals produced naturally by the nervous system to cope with pain or stress. They're like your body's own set of spare keys that can also lock away some level of discomfort or distress.