Melatonin (noun) Definition, Meaning & Examples

noun Physiology.
  1. a hormone secreted by the pineal gland in inverse proportion to the amount of light received by the retina, important in the regulation of biorhythms: in amphibians, it causes a lightening of the skin.
noun
  1. the hormone-like secretion of the pineal gland, causing skin colour changes in some animals and thought to be involved in reproductive function
    Melatonin (noun) Definition, Meaning & Examples

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