Hormones are chemical messengers produced in the body and the contents are secreted directly into the blood. Later it carries to organs and tissues of the body and performs various functions. Hormones are used to communicate between organs and tissues for physiological regulation and behavioral activities, such as digestion, metabolism, respiration, tissue function etc... After being made in one part of the body, they travel to other parts of the body, where organs do their work. Example, insulin is a hormone made by the beta cells in the pancreas. When it's released into the blood, insulin helps regulate how the cells of the body use glucose for energy.