An apocrine gland is one of two types of sweat-producing gland that occur in human skin, the other being eccrine
glands. Apocrine glands are restricted mainly to the armpits and groin.
In response to sex and stress stimuli, they secrete a liquid which is readily
decomposed by bacteria giving rise to odor. The apocrine glands become very
active with the onset of puberty.
Image: © Procter and Gamble