nipple

nipples, a condition of relatively frequent occurrence (1 percent of male and female human population). The nipples usually occur along the primitive milk line, between the armpit and groin, corresponding to the distribution in lower animals. Usually accessory nipples lack mammary tissue, but occasionally, especially…

…breast through cracks in the nipples, the exposed lymphatic ducts, or the milk ducts. Irregular nursing, which leads to overfilling of the breasts, increases the effects of infections. The breasts become swollen, painful, reddened, hardened, and tender. The infection may be in one or both breasts; it can be localized…