Eccrine glands(or merocrine glands) are the major sweat glands of the human body, found in virtually all skin.James, William; Berger, Timothy; Elston, Dirk (2005) Andrews' Diseases of the Skin: Clinical Dermatology (10th ed.). Saunders. Page 6-7. ISBN 0-7216-2921-0.. They produce a clear, odorless substance, consisting primarily of water and NaCl (Note that the odor from sweat is due to bacterial activity on the secretions of the apocrine glands). NaCl is reabsorbed in the duct to reduce salt loss . They are active in thermoregulation, controlled by the hypothalamus.