Normal Breast anatomy

A woman’s breasts are rarely the same size as each other, and may feel different at different times of the menstrual cycle, sometimes becoming lumpy just before a period. They consist of fat, connective tissue , and glandular tissue that contain lobes. Each breast has 15 to 20 lobes. Each lobe is made up of lobules that end in tiny bulbs that can produce milk. A network of milk ducts connects the lobes to the nipple.

The amount of fat in your breasts is largely what determines what size they are. The actual milk-producing structures are nearly the same in all women. Muscles do lie underneath the breasts, separating them from your ribs while oxygen and nutrients are delivered to the breast through arteries and capillaries. The lymphatic system — a network of vessels, lymph ducts and lymph nodes — helps fight off infection. Also there is a network of arteries, veins and nerves