Hormones and pheromones are chemical signals that convey information between organs or individuals. Hormones act at very low concentrations and bind to specific receptors to elicit responses. There are over 50 known hormones in the human body that regulate various processes like metabolism, growth, and reproduction. Pheromones carry messages between individuals, such as signals involved in mate attraction. Local regulators also include growth factors, nitric oxide, and prostaglandins that stimulate specific target cells. The hypothalamus and pituitary gland control other endocrine glands to regulate homeostasis.
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