In animals, control and coordination is performed by neural system and endocrine system jointly. As the nerve fibres do not innervate all cells of the body, the endocrine system is required to coordinate the functions. Endocrine glands are ductless glands. The endocrine glands secrete chemicals called hormones. As the nerve fibres do not innervate all cells of the body and the cellular functions need to be continuously regulated; a special kind of coordination and integration has to be provided. This function is carried out by hormones. The neural system and the endocrine system jointly coordinate and regulate the physiological functions in the body. Some of the topics covered are the human endocrine system, the hypothalamus, the pituitary gland, pineal gland, thyroid gland, parathyroid gland, thymus, adrenal gland, pancreas, testis, ovary, mechanism of hormone action.