An Introduction to Breast Anatomy

Do you know your breast anatomy? Knowing the parts of the breast, what they do and why they are important is critical knowledge for identifying any abnormalities that might appear in the breast.

Do you know why your breasts are so soft? Your breast anatomy does not contain any muscle. Breasts are made up of glandular, fatty, and fibrous tissues. There is a layer of fatty tissue that surrounds the breast glands and runs throughout the entire breast. This fat is what gives breasts their soft consistency. It is also what gives the breast its size and shape.

Inside the glandular tissues of each of your breasts are the functional parts of the breast, including the following:

Each breast is made up of about fifteen to twenty sections or lobes. The lobes are arranged in a circular pattern that resembles a daisy flower. Inside of each lobe are many smaller lobules. The lobules are the milk-producing glands. When a woman is lactating, the bulbs on the end of these lobules produce milk in response to hormonal signals from the mother.

The ducts are the passages that transport the milk from the glands to the nipple. The nipple is located in the center of the colored region known as the areola. This colored area can appear pink to shades of brown.

Once a nursing mother makes milk, it is transported through the ducts to the nipple. As the ducts get closer to the nipple, they get wider to form a sac that is called an ampulla. In your breast anatomy, the spaces between the lobules and the ducts are filled with fat.

Ligaments support and attach your breasts to the front of the chest wall. They attach to both sides of the breastbone or sternum. The breasts are located over the major chest muscle, the pectoralis major.

Both breasts are also comprised of blood vessels and lymph vessels. The outer half of the breast is supplied with blood by the axillary artery extending from the armpit. The inside portion of the breast is supplied with oxygen-rich blood by the internal mammary artery, extending down from the neck.

The lymph vessels in your breast anatomy lead from your breasts to the lymph nodes in your body. Clusters of lymph nodes can be found under your arm, above your collarbone, in your chest, and in many other parts of the body.

Resources

Imaginis. (2004). Breast anatomy and physiology.

National Cancer Institute Surveillance, Epidemiology and End Results (SEER) Program. (nd). Breast anatomy.

University of Maryland Medicine. (2003). Anatomy of the breasts.