The major sweat glands refer to the sweat glands secreted by the parietal plasma of a human being, including the axillary glands, areola glands, eyelash glands, and perianal glands. Sweat glands refers to the human parietal plasma secretion of sweat glands, morphology and small sweat glands similar to the secretion of the major sweat glands with the major sweat glands are different, sweat glands than the small sweat glands for the large, the glands were liquid sac-like excretion, the ducts open in the hair root near the points, cloth in the armpits, the pubic area, the nipple, and around the umbilicus. Its duct is short and straight, opening in the hair follicle, in the sebaceous glands above the exit, generally not involved in thermoregulation. The sweat glands secrete weakly alkaline substances, lipids and thick liquids. Therefore, they are prone to emit a sour and corrosive odor. The secretions of the sweat glands in the armpits are sticky and can emit a foul odor after bacterial decomposition. The sweat glands are located in the hairy parts of the body and their secretion is influenced by hormones in the body.