Hormones are chemicals that are released into the blood and travel all over the

In order for a target cell to respond to a hormone, it must have a receptor. The receptor will have a ligand-binding domain that is specific for certain ligands. (Not all ligands can bind to all receptors.) Thus, only certain hormones will be able to affect a cell. Each receptor also has a functional domain that interacts with the intracellular compartments. Two receptors could have the same ligand-binding domain, which allows them to bind to the same hormone, but have different functional domains. Thus, when the ligand binds the receptor, it will generate the effect associated with its functional domain.