Knowing the various parts of the breast, what they do and why they’re important is critical to identifying any abnormalities that might appear in your breasts. Understanding female breast anatomy can help you understand which changes are normal and healthy, and which may signal disease.
Female Breast Anatomy
Although the human breasts are located over the pectoral muscles of the chest wall, the human breast doesn’t actually contain any muscle tissue. Your breasts, which are made up of glandular, fatty and fibrous tissues, have a number of different functional parts:
- Areola (colored area around the nipple)
- Blood vessels and lymph vessels
- Ducts (milk passages)
- Fatty tissue
- Fibrous tissue that surrounds the lobules and ducts
- Lobules (milk glands)
A layer of fatty tissue surrounds the breast glands and runs throughout the entire breast. This layer of tissue gives the female breast its soft consistency.
Female Breast Milk Production
Each breast has 15 to 20 sections (or “lobes”) beneath the nipple and areola, arranged in a circular pattern that resembles a daisy. Lobes are part of the milk production system; each lobe contains many smaller milk-producing glands called “lobules.” Each lobule has tiny bulbs, called “alveoli.” When a woman is lactating, the alveoli produce milk in response to hormonal signals.
When milk is produced, the ducts transport it from the lobules to the nipple. As each duct gets closer to the nipple, it widens to form a sac called an “ampulla.” The spaces between the lobules and the ducts are filled with fatty tissue, connective tissue and ligaments. As the milk production system is roughly the same size in all women, breast size and shape depend on the amount of fat in the breasts.
Arterial and Lymphatic Anatomy of the Breast
Arteries and capillaries carry oxygen- and nutrient-rich blood to the breasts. The axillary artery, which extends from the armpit, supplies blood to the outer half of the breast. The internal mammary artery, which extends down from the neck, supplies blood to the inner part of the breast.
The human breast also contains lymph vessels. The lymphatic system is part of your immune system and contains blood vessels, lymph ducts and lymph nodes. These work to fight off harmful or infectious substances within your body. Clusters of lymph nodes are located under your arm, above your collarbone, behind your breastbone and in various other parts of your body.
Imaginis Corporation. (2010). Breast anatomy and physiology. Retrieved November 15, 2010, from http://www.imaginis.com/breast-health-non-cancerous/breast-anatomy-and-physiology
Mayo Clinic. (2009). Slide show: Female breast anatomy. Retrieved November 15, 2010, from http://www.mayoclinic.com/health/breast-cancer-early-stage/BC00001
New York-Presbyterian Hospital. (n.d.) Breast anatomy. Retrieved November 15, 2010, from http://nyp.org/health/breast-anatomy.html