The English word breast derives from the Old English word brēost ('breast, bosom') from Proto-Germanic *breustam (breast), from the Proto-Indo-European base bhreus– (to swell, to … See more

In women, the breasts overlie the pectoralis major muscles and extend on average from the level of the second rib to the level of the sixth … See more

The primary function of the breasts, as mammary glands, is the nourishing of an infant with breast milk. Milk is produced in milk-secreting cells in the alveoli. When the breasts are … See more

The breast is susceptible to numerous benign and malignant conditions. The most frequent benign conditions are puerperal mastitis See more

Humans are the only mammals whose breasts become permanently enlarged after sexual maturity (known in humans as puberty). … See more

The breasts are principally composed of adipose, glandular, and connective tissues. Because these tissues have hormone receptors, their sizes and volumes fluctuate according to the hormonal changes particular to thelarche (sprouting of … See more

Biomechanical studies have demonstrated that, depending on the activity and the size of a woman's breast, when she walks or runs braless, her breasts may move up and down by 4 to 18 centimetres (1.6 to 7.1 in) or more, and also oscillate side to side. Researchers … See more