The endocrine system is really a fascinating and intricate organization of glands that produce and secrete hormones to the bloodstream, affecting just about every cell and organ in the body of a human. These endocrine glands are our principal hormone producers you need to include the hypothalamus, pituitary (considered the master gland since it regulates the functions of countless other organs and glands), thyroid, adrenals, as well as the reproductive glands. They are ductless glands which have a network of capillaries running through them which offers direct access towards the bloodstream.