Nociceptors: Specialized nerve endings that detect painful stimuli. They send signals to the brain, triggering the sensation of pain.
Gate Control Theory: This theory suggests that there are "gates" in the spinal cord that can open or close, modulating the perception of pain. For example, rubbing a bumped knee may help alleviate some pain by activating other sensory pathways.
Endorphins: These are natural painkillers produced by our bodies. They bind to opioid receptors in the brain, reducing the perception of pain and creating feelings of pleasure or euphoria.