The milk is made in the alveoli (grape) and travels down the ducts (stems) going from the smallest duct to the largest ending at a small pouch just under the areola, called the lactiferous sinus (which would be like a widening in the thickest part of the stem). The hormone estrogen promotes the growth and branching of this ductal system. Prolactin and other hormones also contribute to breast growth in pregnancy and preparation for breastfeeding.
Women may notice the darker skin around the nipple, the areola, increasing in diameter and getting deeper in color. It is believed that the darker color of the areola serves a purpose by helping the newborn to spot the nipple. The Montgomery glands, the small pimple-like glands on the areola, also enlarge during pregnancy. The role of the Montgomery glands is to secrete a substance that lubricates and helps to protec
at 1:46 AM on Jun. 9, 2009