In What Ways the Hormones Work for Human Body and Healthy Living?
The special chemicals known as hormones regulate the various physiological activities of animals as well humans. The hormones are produced by special glands called endocrine glands. These glands do not have any ducts to carry their secretions to the target organs and they release their secretions directly into the blood stream. The hormones are secreted in response to the specific stimuli arising from within the body or outside the body. Hormones are called informational molecules which stimulate or inhibit specific biological activity in the target organs.
Hormones may be, chemically, either steroids (example sex hormones, cortisol) or amino acid tyrosine derivatives (e.g. thyroxin) or proteins or peptides (e.g. insulin, glucagons). Hormones are secreted in very minute quantities and their actions are highly specific and affect only particular target organs