The Endocrine System
The endocrine system comprises a number of glands that produce hormones with a varied array of vital functions. Hormones are chemical substances that are secreted by organs or by cells of organs in one part of the body and are carried by the bloodstream to other organs or tissues, where they control or regulate the development or function of those structures.
Endocrine glands are also called ductless glands, because they secrete hormones directly into the bloodstream. In contrast, exocrine glands release their secretions through ducts (for example, the sweat glands produce fluid that flows to the skin's surface through tiny tubelike sweat ducts).
Hormones can be considered chemical messengers. They are targeted at specific cells in the body, and their arrival in those cells causes specific activities to occur.
One of the major tasks of hormones is to coordinate the activities of organ systems. For example, when a person has to run, the hormone epinephrine acts on the heart to increase its rate and force of contraction; it acts on the blood vessels to increase blood flow to the muscles and decrease blood flow to the gastrointestinal tract. Hormones also help control the type and rate of body growth and metabolism, and they help the body maintain a consistent internal environment.
The endocrine system has a large influence on the way we feel and act. In turn, our energy and other needs in any given situation set the activity of the endocrine system. This feedback relationship is crucial in maintaining our general well-being.
Now let's look at the major components of the endocrine system in the next section.
This information is solely for informational purposes. IT IS NOT INTENDED TO PROVIDE MEDICAL ADVICE. Neither the Editors of Consumer Guide (R), Publications International, Ltd., the author nor publisher take responsibility for any possible consequences from any treatment, procedure, exercise, dietary modification, action or application of medication which results from reading or following the information contained in this information. The publication of this information does not constitute the practice of medicine, and this information does not replace the advice of your physician or other health care provider. Before undertaking any course of treatment, the reader must seek the advice of their physician or other health care provider.
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