The breast of an adult woman is a tear-shaped, milk producing gland, supported and attached to the chest wall by ligaments, which are fibrous strands. The breast is made up of glandular tissue (lobes and lobules – milk producing glands), fat and fibrous tissues. Fatty tissue surrounds the glands and ducts. Milk glands are lobules that produce milk and this is transported through the ducts to the nipple. The breasts are rarely symmetrical and of the same size / shape / location; one breast may be larger or smaller, higher or lower or shaped differently as compared to the other breast.
A woman’s breasts are continuously changing from puberty to menopause depending on the hormonal cycles of the body. It is important to know the breast anatomy to be able to comprehend the normal changes and also detect anything unusual like lumps. Eestrogen and progesterone that are produced during puberty, signal the growth of the breast tissue. The fat and fibrous tissue become more elastic. The areola houses tiny, raised bumps called Montgomery’s glands, which help lubricate the areola. Younger women have more glandular tissue.
External anatomy of the breast
- Montgomery’s gland
- Morgagni’s tubercles
- Axillary tail
- Fibrous tissue
- Glandular tissues (lobes and lobules)
- Lymphatic channels
- Circulatory system
Microscopy of the glands
- The gland has a row of cells.
- These cells sit on a basement membrane.
- Inside is the lumen
A hormone called estrogen helps in the growth of the glands of the breasts during puberty. Once ovulation begins during teen years, breast development is completed. Fluctuations in hormonal levels during the menstrual cycles are the reason for the change in size, firmness and tenderness that some women experience during their periods and also a week to ten days before.
During pregnancy, the hormones prepare the mother’s breasts for milk production. The glands and ducts grow and the breast swells. With age, particularly after menopause, the reduction in hormone levels causes the breast to lose its firmness as the glandular tissue shrinks and almost 90% breast is replaced by fat.
Factors governing breast size
- Volume of breast tissue
- Family history
- Weight loss or gain
- History of pregnancies and lactation
- Degree of hormonal influences on breast (estrogen and progesterone)