<Table> <Tr> <Td> </Td> <Td> This article needs more medical references for verification or relies too heavily on primary sources . Please review the contents of the article and add the appropriate references if you can . Unsourced or poorly sourced material may be challenged and removed . (May 2014) </Td> <Td> </Td> </Tr> </Table> <Tr> <Td> </Td> <Td> This article needs more medical references for verification or relies too heavily on primary sources . Please review the contents of the article and add the appropriate references if you can . Unsourced or poorly sourced material may be challenged and removed . (May 2014) </Td> <Td> </Td> </Tr> <P> Endorphins (contracted from "endogenous morphine") are endogenous opioid neuropeptides and peptide hormones in humans and other animals . They are produced by the central nervous system and the pituitary gland . The term "endorphins" implies a pharmacological activity (analogous to the activity of the corticosteroid category of biochemicals) as opposed to a specific chemical formulation . It consists 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 class of endorphins includes three compounds--α - endorphin, β - endorphin, and γ - endorphin--which preferentially bind to μ - opioid receptors . 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 . </P> <P> The class of endorphins includes three endogenous opioid peptides: </P>

What is the body natural version of morphine