The endocrine system is made up of the many glands in the body, the hormones that the glands make and release into the bloodstream or the fluid around the cells, and the receptors in different organs and tissues that sense the hormones and respond to them. Several hormones work by attaching to receptors made by cells, much like a lock and key. Hormones characteristics feature and mechanism of work is a complicated process in the body accordingly the aim or writing about this subject is to make it easier for students and junior chemists in the field of chemistry to understand how the cycle...