endorphins

When you exercise or being spanked, your body releases chemicals called endorphins, which are produced by the central nervous system and the pituitary gland. These endorphins interact with the receptors in your brain that reduce your perception of pain.


Endorphins consist of two parts: endo- and -orphin; these are short forms of the words endogenous and morphine, intended to mean "a morphine-like substance originating from within the body". The principal function of endorphins is to inhibit the transmission of pain signals; they may also produce a feeling of euphoria very similar to that produced by other opioids.

Endorphins also trigger a positive feeling in the body, similar to that of morphine. For example, the feeling that follows a run or workout is often described as "euphoric." That feeling, known as a "runner's high," can be accompanied by a positive and energizing outlook on life.

They also act as sedatives. They are manufactured in your brain, spinal cord, and many other parts of your body and are released in response to brain chemicals called neurotransmitters. The neuron receptors endorphins bind to are the same ones that bind some pain medicines. However, unlike with morphine, the activation of these receptors by the body's endorphins does not lead to addiction or dependence.