Breast Anatomy

It is important for women and men to understand the normal anatomy and function of their breasts so that any abnormalities can be detected and treated.

The breast is a mass of glandular, fatty and fibrous tissues positioned over the pectoral muscles of the chest wall. A layer of fatty tissue surrounds the breast glands and extends throughout the breast. The fatty tissue gives the breast a soft consistency.

The glandular tissues of the breast store the lobules (milk producing glands at the ends of the lobes) and the ducts (milk passages). During lactation, the ducts at the ends of the lobules produce milk. Once milk is produced, it is transferred through the ducts to the nipple.

Female hormones such as oestrogen and progesterone are important in promoting growth and changes that occur in the breast, especially during pregnancy and the menstrual cycle.

In men, the development of the lobules is suppresses at puberty by testosterone, the male sex hormone.

The axillary artery extends from the armpit and supplies the outer half of the breast with blood. The internal mammary artery extends down from neck and supplies the inner portion of the breast.