RT Book, Section A1 Zouboulis, Christos C. A1 Tsatsou, Fragkiski A2 Goldsmith, Lowell A. A2 Katz, Stephen I. A2 Gilchrest, Barbara A. A2 Paller, Amy S. A2 Leffell, David J. A2 Wolff, Klaus SR Print(0) ID 56048561 T1 Chapter 85. Disorders of the Apocrine Sweat Glands T2 Fitzpatrick's Dermatology in General Medicine, 8e YR 2012 FD 2012 PB The McGraw-Hill Companies PP New York, NY SN 978-0-07-166904-7 LK accessmedicine.mhmedical.com/content.aspx?aid=56048561 RD 2024/03/29 AB Apocrine glands are adnexal glands that are distributed in the scalp, the axillae, the anogenital region, the eyelids (Moll's glands), the external auditory meatus (ceruminous glands), and the mammary glands. Apocrine glands can also be found in a more limited distribution on the face and abdomen. Apocrine glands are quiescent until puberty. Embryologically, apocrine glands develop from the upper bulge of the hair follicle late in the fourth month of gestation, with continued development as long as hair follicles develop. A primary epithelial germ (hair germ) grows down from the epidermis and forms an apocrine gland, sebaceous gland, and hair follicle. Apocrine glands are composed of three components: (1) the intraepithelial duct, (2) the intradermal duct, and (3) a coiled gland in the deep dermis or at the junction of the dermis and subcutaneous fat, which contains the secretory portion. The coiled gland consists of one layer of secretory cells around a lumen that is about ten times the diameter of its eccrine counterpart. Contractile myoepithelial cells, a hyaline basement membrane, and connective tissue surround the coiled gland. The predominant mode of apocrine secretion is decapitation, a process where the apical portion of the secretory cell cytoplasm pinches off and enters the lumen of the gland. Apocrine sweat consists mainly of sialomucin. Apocrine sweat is more viscous and produced in much smaller amounts than eccrine sweat (which actually is the wet portion of axillary sweat). The exact function of apocrine glands is unclear, although they are thought to represent scent glands. Their primary sympathetic stimulation is adrenergic.1