There are two types of glands - endocrine and exocrine glands. Exocrine glands secrete hormones through the duct and not directly into the bloodstream, unlike endocrine glands. So, exocrine glands do not secrete substances into the bloodstream. These glands can be found, not only in the skin and mouth but also in digestive or respiratory tracts. They also have a variety of functions.
Sometimes, exocrine glands, such as lacrimal or sweat glands can release substances out of the body.