Right now, I want you to be able to identify endocrine, unicellular exocrine, multicellular exocrine glands when you see them. I also want you to tell me where they are located in the body and what are the basic differences between the three. You will learn to do that later on.
Hormones act as chemical messengers to regulate specific body functions.
Endocrine glands are formed by invagination from an epithelial sheet and initially have ducts connecting them to the free surface of the epithelial sheet. We will learn more about them later in the year. Their products are NOT released into the blood. They have no ducts, of course, but they secrete their products directly on the free surface of open body cavities and thus, are considered exocrine. Multicellular glands are multicelled glands.