Structure and Function of Human Sweat Glands

Sweating is the elaboration of a fluid secretion on the general body surface produced by sweat glands within the skin. These glands are developed only in mammals, in which they evolved, along with sebaceous glands, as furconditioning organs and for defense at the skin surface against microbial invasion. While most mammals possess at least rudimentary sweat glands, surprisingly, it is only in higher primates, horses, and some Bovidae, that the organs play a truly major role in the critical physiological function of thermoregulation. A plains-living ancestry, with the need of sustained effort to evade predators, may have been the common evolutionary stimulus. In other mammalsthe function of the gland seems to be primarily limited to producing substances required for maintenance of a healthy skin or for lubricating contact surfaces, e.g., footpads, eyelids, or palms; here the gland is much less involved in temperature control (1).