My Breakthrough
Basic female breast biology
This section aims to give you practical information about the healthy female breast and what you can do to make sure that your breasts stay healthy.
Visit our section on breast awareness and risk factors to get more information about prevention and early detection.
The healthy female breast
Your breasts are mainly made up of fatty tissue containing thousands of tiny glands or lobules, designed to produce milk in late pregnancy and after childbirth. These lobules make up lobes that empty into tubes or ducts. These ducts connect together and channel to the nipples, delivering milk for breast-feeding.
Each breast contains 5-10 ductal systems, 15-20 lobes - and roughly 1 million lobules.
The nipple is surrounded by the areola, a darker area. Glands in the areola produce fluid to lubricate the nipple during breastfeeding.
The remainder of each breast is made up of surrounding fatty and connective tissue. Ligaments and large muscles attached to the chest wall provide support.
Each of your breasts is distinct. They may not be exactly the same size or shape - for instance, one may be larger than the other - and this is quite normal. Similarly, whilst your nipples usually point forward, they may look different on each breast. One or both of them may be inverted (turned inward) from an early age. Again, these differences aren't unusual.
Your breasts' size and shape are likely to vary in different situations. For example, the changing levels of hormones present during the menstrual cycle can affect your breasts. They may also feel tender or lumpy just before your period - this is also normal. Your breast size is also likely to vary during pregnancy, as changing levels of hormones help your body prepare for breastfeeding.
The appearance and composition of your breasts will also change with age and corresponding changes in hormone levels. For instance, after the menopause (change of life) they may become softer and smaller as more of the glandular tissue designed for breastfeeding is replaced by fat.
Breast tissue actually extends beyond the visible breast into the axilla (armpit). In the armpit and breast area there are many lymph nodes (glands). These nodes contain 'fighter' cells that act as filters as fluid and cells from the breast pass through the node. They form part of the lymphatic system, which helps the body to fight infection.
But the role of the breast is far more complex than the practical function of providing milk for babies. In our society, breasts are also regarded as symbols of beauty and femininity - part not only of a woman's role as a mother, but also as a visible sign of her female sexuality.
Breasts have an emotional and psychological role to play and have an impact on issues such as body-image and self-confidence.
Also within "Understanding breast cancer"
- Basic female breast biology
- Are all lumps cancer?
- Statistics
- Lifetime risk
- Quiz
- Clinical trials
