Human Growth Hormone

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What Are The Functions Of The Endocrine System

An informative article on: What Are The Functions Of The Endocrine System.

The chief function of the endocrine system is to release hormones directly into the blood to act as messengers that control and coordinate activities throughout the entire body. Each hormone controls at least one physiological function within one area of the body, but some control functions throughout the entire body. Hormones are either proteins, which makes up the largest percentage, or steroids and they control growth and development, reproduction, sexual characteristics, metabolism, volume of fluids in the body, levels of salts and sugar in the blood. Hormones can also act as communicators outside the body, between two individuals.

Two Methods of Signaling

Local signaling is the first method and it involves the release of hormones by a cell or a gland into interstitial fluids to signal a response in nearby cells. The second method is known as long distance signaling. Hormones are released into the bloodstream to be carried to areas of the body where a receptor cell awaits a signal to activate in order to perform a function.

Growth and Development

The development and growth of new cells is controlled by hormones. Growth hormones signal both the commencement as well as the rate of growth. During research it was substantiated that laboratory mice that had been injected with EGF, epithelial growth factor, evidenced faster skin growth.

Reproduction

Estrogens, progesterone, testosterone, luteinizing hormones and follicle stimulating hormones are the main hormones secreted by the endocrine system that are necessary to reproduction. These hormones function to signal the reproductive system to respond in certain ways. For instance, the luteinizing hormone signals the ovary to release an egg to the fallopian tube to await fertilization.

Secondary Sexual Characteristics

Although not primarily part of the reproductive system, secondary sexual hormones function to determine the physical characteristics of males and females. As an example, they determine facial hair on males and the size of breasts in females. These hormones secreted by the endocrine system signal the development of the testes and penis in males as well as the ovaries in females.

Metabolism

Hormones that are secreted by the endocrine glands also function to regulate the way the body uses and stores energy. Probably the most well known hormone of this type is insulin which is secreted by the pancreas to control the metabolism of both sugars and lipids.

External Communicators outside the Body

Pheromones differ from hormones in that they function as external communicators outside the body. They are secreted from sweat glands, primarily the underarms, and are known to signal a response between individuals. Pheromones are known to act as communicators between animals of the same species. There is mounting evidence to suggest that they affect the way individuals react to each other.

So then, the endocrine system functions by releasing chemicals that signal a response in a receptor site. That site can be internal to the body, either in close proximity to the site where they are secreted or elsewhere throughout the body. And other chemicals released, such as pheromones, function by signaling a response between individuals of the same species.