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Medical Author:

Melissa Conrad Stöppler, MD

Melissa Conrad Stöppler, MD

Melissa Conrad Stöppler, MD, is a U.S. board-certified Anatomic Pathologist with subspecialty training in the fields of Experimental and Molecular Pathology. Dr. Stöppler's educational background includes a BA with Highest Distinction from the University of Virginia and an MD from the University of North Carolina. She completed residency training in Anatomic Pathology at Georgetown University followed by subspecialty fellowship training in molecular diagnostics and experimental pathology.

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Medical Editor:

William C. Shiel Jr., MD, FACP, FACR

William C. Shiel Jr., MD, FACP, FACR

Dr. Shiel received a Bachelor of Science degree with honors from the University of Notre Dame. There he was involved in research in radiation biology and received the Huisking Scholarship. After graduating from St. Louis University School of Medicine, he completed his Internal Medicine residency and Rheumatology fellowship at the University of California, Irvine. He is board-certified in Internal Medicine and Rheumatology.

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In this Article

• What is the breast?
• How is the mammary gland designed?
• How are human breasts different from those of other primates?
• What happens to the breasts in pregnancy?
• What is the function of the nipples and surrounding pigmented tissue?
• What are other internal features of the breast?
• What are cosmetic aspects of the breast?
• How does breast tissue develop in the fetus?
• What are the most common medical concerns about the breast?
• Breast Index

The nipple becomes erect because of such stimuli as a cold environment, breastfeeding, and sexual activity. The nipple of the post-partum female is used by the infant to breastfeed.

The small darkened (pigmented) area around the nipple is called the areola. (The word "areola" is the diminutive of the Latin "area" meaning a small space.) In pregnancy the areola darkens further and spreads in size. The areola contains small modified sweat glands (Montgomery's glands) that secrete moisture that acts as a lubricant for breastfeeding.

The lobules and ducts in the breast are supported by surrounding fatty tissue and the suspensory ligaments of the breast. There are no muscles in the breast. However, the breast tissue is located on top of the muscles of the chest wall. The characteristic bounce of the breast comes from the elasticity of the matrix of connective tissue fibers in the breast.

There are blood vessels and lymphatic vessels in the breast. The lymphatic vessels are thin channels similar to blood vessels; they do not carry blood but collect and carry tissue fluid which ultimately re-enters the blood stream. Breast tissue fluid drains through the lymphatics into the lymph nodes located in the underarm (axilla) and behind the breast bone (sternum).