The Endocrine System
The endocrine system is composed of various glands; the adrenal, gonads, ovaries, pancreas, parathyroids, pineal, testes, thymus, and thyroid. The system is responsible for the hormone or internal secretion produced by the endocrine gland regulating the body's vital internal processes and guides critical phases of prenatal development. The system is formed of those body organs whose function is to prepare internal secretions and deliver them to the blood or lymph. 2
The endocrine glands produce and release hormones into the bloodstream. They are chemical messengers that circulate in the blood and regulate many critical biological functions through intricate signaling mechanisms. 3 The pituitary gland lies beneath the brain and acts as a control center for the endocrine system. It informs the thyroid or ovaries when to send their chemical messages, and how much to send. The pituitary gets its cues from the hypothalamus, a nearby small center under the brain that constantly monitors the hormone levels in the blood. It sends a message to the pituitary if levels of a hormone get too high or too low. The pituitary then signals the gland that produces this hormone to gear up, slow down or shut off. Thus a woman's ovaries release estrogens - the female hormones that travel in the bloodstream to the uterus, where they trigger growth of the tissue lining of the womb in anticipation of a possible pregnancy. 4
The pituitary is also responsible for making the luteinising and follicle stimulating hormones. In men these hormones are sent to the testes where the luteinising hormone stimulates the production of the male hormone testosterone. The follicle stimulating hormones in turn are important in sperm production. 5
In normal healthy vertebrates the endocrine system works smoothly sending and receiving messages that keep the body functioning properly and reproducing healthy offspring. But, during the past forty or so years more and more animals including humans have developed infirmities, abnormalities, and behavior changes that were either unknown or were extremely rare. Scientists have been able to determine that many can be attributed to synthetic chemicals that mimic hormones and confuse the messages in the endocrine system, causing it to malfunction.
Since one of the endocrine systems functions is to insure the replication of the organism to which it belongs; abnormalities in the gonadal region would certainly be an impediment toward achieving the goal. Some of the abnormalities are easily detectable at birth but others only become obvious in adulthood when undeveloped reproductive organs or infertility stand in the way of normal reproduction. Early adolescence is another example of disrupted endocrine with girls reaching menarche as early as eight years of age. Behavioral changes that have been found to relate to endocrine disruption are hyperactivity and autism. 6
Comments: