This book focuses on hormones & on how they are produced in very diverse regions of the body in humans & animals But hormones can be found not only in vertebrates but also in insects shellfish spiders mollusks even at the origin of metazoan diversification & exhibit the same pathways of synthesis The book addresses the different classes of hormones proteinpeptides hormones steroids & juvenile hormones & hormones like catecholamines thyroid hormones & melatonin It also discusses the types of hormone receptors the majority of which are heptahelical G-protein coupled receptors or nuclear receptors Particular attention is paid to the organs where hormones are created with specifics on hormonal production & release while a dedicated chapter details hormonal regulation from very simple to highly complex schemes The remarkable kinetics of hormones production are also shown before the book is rounded out by chapters on evolution in the endocrine system the genetics of endocrine diseases & doping