Endocrine System
This article is written with the massage therapist in mind for review and to server as a guide in helping pass the national exam. 
Endocrine system - The Function of the endocrine system is communication and control which is the same as the nervous system yet it is much slower than the nervous system. The endocrine system last much longer than the endocrine system do in communication and control. The endocrine system uses hormones as its message carriers through circulated blood within the body. Hormones are chemicals that are secreted into and circulated in the blood, as well as being chemical messengers produced by the endocrine system. The two types of glands in the body are endocrine and exocrine. Exocrine gland secrete their products into ducts that empty onto a surface or into a cavity. Some examples of exocrine glands are salivary glands, and sweat glands. Endocrine glands are known as ductless glands.
Endocrine glands secrete chemicals into inter-cellular spaces which diffuse directly into the blood stream. Hormones bind to the target organ cells at the receptor sites of the cell and trigger reactions in the cell. Tumors can cause glands to produce too much or too little hormones causing imbalances and abnormal growths in the body. Hyper-secretion is the production of too much of a hormone by a diseased gland in the body, yet hypo-secretion is the opposite the production of too little of a particular hormone.
There are two major categories of hormones non-steroidal and steroidal. The chemicals or hormones fit into receptor sites like a lock and key in the cells function. Non steroids are whole proteins, shorter chains of amino acids, or versions of single amino acids. Steroids are lipid-soluble hormones which can pass intact directly through the cell membrane of target organ cells an example of this would be estrogen.
The body regulates itself through the secretion of most hormones in attempts to reverse any deviations from normal through a negative feedback loop. Some of the hormones that the body uses are insulin which lowers blood sugar levels, and insulin is released by the pancreas. Low blood sugar levels cause a decrease in the production and release of insulin into the bodies blood stream. This causes the negative feedback loop to bring the bloods sugar level back to normal once it has strayed from normal, reversing the change in chemical levels in the body.
