Endocrine System
In endocrine system ductless gland or specialized cells release chemicals called hormones into the circulating blood. These hormones influence the functions of cells at another location in the body. The endocrine glands are pituitary, thyroid, adrenal, pancreas, parathyroid, testes and ovaries. You will learn in Unit 3 of Block 1 about pancreas and its functions and that the alpha cells secrete glucagon and the beta cells secrete insulin.