"hormone" was introduced in 190 by a British physiologist, Professor Ernest Starling . It is derived from the Greek verb hormao, which means "set in motion fast, excite, stimulate". Hormones are involved in almost all biological processes: immune function, reproduction, growth, and even control of other hormones. They can act at surprisingly low concentrations (one part per billion 10 or trillion 10 12). One of the most interesting is the hormone Strength Muscles. When "speaks," everyone listens Researcher James McBride Dabbs, was one of the world's leading experts on and its effects on men and women. In his book Heroes, Rogues, and Lovers: and Behavior "Heroes, Bandits and Lovers: and Behavior ," he .