Endocrine system gonads, have secondary endocrine functions. For example, the kidney secretes endocrine hormones such as erythropoietin and renin. Hormones can consist of either amino acid complexes, steroids, eicosanoids, leukotrienes, or prostaglandins. The endocrine system is in contrast to the exocrine system, which secretes its hormones to the outside of the body using ducts. As opposed to endocrine factors that travel considerably longer distances via the circulatory system, other signaling molecules, such as paracrine factors involved in paracrine signalling diffuse over a relatively short distance. The word "endocrine" derives via New Latin from the Greek words , "endon", "inside, within," and ,
Endocrine disruptor are appropriate", however this study was conducted over a year before the EPA announced the final structure of the screening program. The EPA is still finding it difficult to execute a credible and efficient endocrine testing program. As of 2016, the EPA had estrogen screening results for 1,800 chemicals. In 2013, a number of pesticides containing endocrine disrupting chemicals were in draft EU criteria to be banned. On the 2nd May, US TTIP negotiators insisted the EU drop the criteria. They stated that a risk-based approach should be taken on regulation. Later the same day Catherine Day wrote to Karl