Pharmacokinetics (in Greek: "pharmacon" meaning rug and "kinetikos" meaning putting in motion, the study of time dependency) is a branch of pharmacology dedicated to the determination of the fate of substances administered externally to a living organism. In practice, this discipline is applied mainly to drug substances, though in principle it concerns itself with all manner of compounds ingested or otherwise delivered externally to an organism, such as nutrients, metabolites, hormones, toxins, etc. Pharmacokinetics is often divided into several areas including, but not limited to, the extent and rate of Absorption, Distribution, Metabolism and Excretion. This sometimes is referred to as the ADME scheme.