Hormone

endogenous active substance derived from endocrine glands, tissues or cell groups are formed and released into the blood. Hormones are chemically specific low- or higher molecular weight Substances which, in very low concentrations, regulate metabolic processes, growth, reproductive functions, nervous activity, etc. Some hormones have only a locally limited effect (tissue hormones).

Within a living being, hormones transmit information from one organ to another or from one tissue to another. In contrast to the high speed of the information transmitted by nerves, a few seconds (e.g. adrenalin) to hours can pass between the hormone release and its effect. Hormones in animal life are transported through the bloodstream to their target organs. An exception are tissue hormones, which are produced and act in the same organ.

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