They help regulate body heat. Eccrine glands are simple coiled glands . Their secretory epithelium is usually simple cuboidal or columnar with two cell types being recognized. They are supplied by postganglionic sympathetic nerve fibers that are cholinergic. Dark cells and clear cells are the secretory cells.
Dark cells produce a mucous-like secretion while clear cells make an aqueous secretion.
The ducts are composed of stratified cuboidal epithelium, and these open onto the skin surface. These are located in the axilla, perianal region, external genitalia, and areola of the nipples. Their secretory units are composed of a simple cuboidal or columnar epithelium and only one cellular type is present. Their secretion is more viscous than that of eccrine glands. Their ducts are like those of the eccrine glands, but they open into hair follicles instead of the surface of the skin.