Homeostasis-This is a term used by physiologists and refers to maintenance of constant conditions of the internal environment of the body. All of the organs work to maintain these constant conditions, through feedback mechanisms. For example, in the male, testosterone is produced in the interstitial leydig cells of testes. The average male produces from anywhere, up to 25 mg/day. Testosterone production in the testes is stimulated from luteinizing hormone (LH) in the anterior portion of the pituitary gland in the brain. If the testes attempt to produce more than is required, the higher than normal amounts of testosterone in the blood turn off LH production in the pituitary. With a decrease in LH, the testes are no longer stimulated to produce testosterone and production halts until testosterone levels lower. If testosterone production were permitted to go unchecked, then excessive amounts of testosterone would be produced and disease may result. This is an example of a homeostatic mechanism and there are thousands of them which keep strict control on all functions throughout body. This is what keeps us healthy.