Endocrine gland hormones at target cells "Permissiveness" is the situation in which a hormone cannot exert its full effects without the presence of another hormone. "Synergism" occurs when two or more hormones produce the same effects in a target cell and their results are amplified. "Antagonism" occurs when a hormone opposes or reverses the effect of another hormone. The endocrine glands belong to the body's control system. The hormones which they produce help to regulate the functions of cells and tissues throughout the body. Endocrine organs are activated to release their hormones by humoral, neural or hormonal stimuli. Negative feedback is important
Endocrine disruptor to a lot of controversy due its potential estrogenic effect in humans. Tributyltin (TBT) are organotin compounds that for 40 years TBT was used as a biocide in anti-fouling paint, commonly known as bottom paint. TBT has been shown to impact invertebrate and vertebrate development, disrupting the endocrine system, resulting in masculinization, lower survival rates, as well as many health problems in mammals. Since being banned, the average human body burdens of DDT and PCB have been declining. Since their ban in 1972, the PCB body burden in 2009 is one-hundredth of what it was in the early 1980s. On