What is a breast?

Breasts are glands that can make milk. Each breast is above the pectoral muscles that cover the ribs. Each breast consists of 15-20 parts called lobes. The lobes cover the small lobules. Lobules contain small glands that produce milk. Milk flows from the nipple by passing through lobules and thin channels called ducts. The nipple is the center of the dark skin area called the areola. Fat fills between the lobules and ducts. The breasts also contain lymph channels that carry a colorless fluid called lymph. Lymph channels open into small round lymph nodes. Groups of lymph nodes are found next to the breast in the armpit, above the collarbone, behind the sternum (belly bone), and in other parts of the body. Lymph nodes hold bacteria, cancer cells and other harmful components that may be in the lymphatic system.