What is the structure of mammary glands?
The mammary glands are tree-like structures with tiny sacs called alveoli at the tips of the branches. These small sacs contain the milk-producing cells and milk is stored in these sacs during lactation. When the breast is stimulated by hormones, muscles around the alveoli contract and force the milk into connecting ductules. These ductures meet to form larger ducts that exit the breast at the nipple. About 5 to 10 ducts have visible openings on the outside tip of the nipple.
