A Guide to the Organs of the Endocrine System and How They Work
written by: Jason C. Chavis•edited by: Lamar Stonecypher•updated: 4/18/2010
By using a series of signals, the glands of the endocrine system create a communication network known as an axis. Endocrinologists study this system and its relation to diabetes, obesity and other endocrine conditions.
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How does the endocrine system work? The basic way the endocrine system works is through an elaborate structure of glands, each secreting hormones. Endocrine glands work similar to nerves in that they rely on various signals to operate, releasing the hormones depending on external and internal information. In this way, the system can regulate nearly every function of the human body from metabolism to general mood. Among the most important aspects of the endocrine system is growth and development of tissues and organs. When a person studies how the endocrine system works, the branch of science is known as endocrinology.
Above right: Endocrine System. (Supplied by the U.S. Federal Government; Public Domain; http://upload.wikimedia.org/wikipedia/commons/c/c6/Illu_endocrine_system.jpg)
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Signaling in the Endocrine System
How does the endocrine system work with signals? Glands of the endocrine system receive signals from outside stimuli. When a particular gland determines it is time to release a hormone, it signals other glands and hormone-producing agents to likewise release signals. This is called an axis. Each gland and organ work in unison to achieve a goal. For example, if a person is stimulated from some form of excitement, the hypothalamus sends out a signal to the pituitary gland, which in turn sends a signal to produce adrenaline in the adrenal glands. Secondary hormones are also released during this process which impacts the immune system, digestion, and energy expenditure.
Additional types of endocrine signaling exist on the cellular level. While these still work with hormones, the level of production is far smaller than axis signaling. Autocrine signaling takes place within the cell itself, when a hormone is released through a chemical messenger that binds with receptors, creating a change in the cell. Juxtacrine signaling occurs between adjacent cells with plasma membranes in contact with each other. This causes actions in the adjacent cell or within both cells.
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Malfunctions in the Endocrine System
Commonly, things go wrong with the endocrine system that can affect the way glands work and thereby the entire human body in general. A wide variety of disorders and diseases can develop either over the course of time or suddenly which cause drastic problems. Among the most common examples of these disorders are diabetes, hypothyroidism, obesity and the development of goiters.
These conditions are known as endocrinopathies and are divided into three different formats: primary, secondary, and tertiary. Primary endocrinopathies are the result of a failure of the glands to produce hormones. Secondary conditions are those associated only with the pituitary gland, often caused by tumors known as adenomas. Tertiary concerns are those where the hypothalamus fails to function properly. This condition can result in large-scale glandular failure.
How does the endocrine system work when a disease develops? A variety of situations can arise when a person develops a endocrinopathy. The most common is irregular hormone production, misinterpreting signals or releasing too many hormones at one time. However, other conditions such as enlargements or a loss of a gland can lead to these problems.