Several organs within the human body make up the endocrine system. These organs include the ovary, testes, thyroid and adrenal glands, pancreas, pituitary, as well as the placenta, liver, kidneys and cells of the gastrointestinal tract. Understanding the role of these organs in the normal functioning of the body gives us some indication of the types of problems that might occur when proper endocrine function is disrupted. Moreover, many of these organs influence each other's activities, producing very complex interactions and making the effect of disruptors exceedingly difficult to identify or predict. Endocrine systems can be affected by certain substances outside of the body, both naturally-occurring and artificial.
Substances can disrupt the normal function of endocrine systems in three different ways.
One, they can mimic a natural hormone, and lock onto a receptor within the cell. The disruptor may give a signal stronger than the natural hormone or at the wrong time. In some cases even very small amounts of a disruptor may have a detectable effect. Two, they can bind to a receptor within a cell, and prevent the correct hormone from binding. The normal signal then fails to occur and the body fails to respond properly.