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Breast Anatomy - What Are The Parts of a Nipple and Areola?


Updated April 10, 2014

Written or reviewed by a board-certified physician. See About.com's Medical Review Board.

Nipple Anatomy

Nipple Anatomy - A Simple View

Art © Pam Stephan
Question: Breast Anatomy - What Are The Parts of a Nipple and Areola?
In terms of breast anatomy, your nipple is the crowning touch. Your nipple is at the business end of the breast milk system, the first place a newborn baby will seek out. It may be the place your partner likes to target, as it is very sensitive to touch and temperature. What's inside your nipple and areola? Learn about the inner workings of your outermost breast anatomy.

Milk Ducts: Milk ducts are small tubes that transport milk from the milk glands (lobules) out the tip of the nipple. Ducts are lined with myoepithelial cells. Mastitis is a condition in which a breast duct becomes plugged.

Most types of breast cancer start to develop in the ducts. Ductal carcinoma in situ and invasive ductal carcinoma originate in the milk ducts. A ductogram or the Halo test may be used to examine breast fluid or ductal cells.

Milk Duct Orifices: Breast milk is released from holes at your nipple's surface called milk duct orifices. You will have two or three of these holes in the center of your nipple, and three to five more arranged around the center. These holes have tiny sphincters that close to prevent leakage when you are not breastfeeding.

Ampulla: The ducts just below your areola widen before they enter your nipple. This wide, sac-like area is called an ampulla. Sometimes the ampullae are called frontal ducts.

Areola: Surrounding the nipple is your areola, an area of skin that is darker than the rest of your breast skin. Small bumps on the areola may be either Montgomery's glands or hair follicles.

Your areola may be small or large, round or oval. During pregnancy, it may grow in diameter. But if you notice a change in your areola skin, such as dimples, puckers, or a rash, check with your doctor. These might be harmless, but could also be symptoms of Paget's Disease.

Montgomery's Glands: These special glands live just below the surface of your areola and may be seen as small bumps in the skin. Also called areolar glands, these provide lubrication during breastfeeding. Montgomery's glands may become blocked, like pimples, and swell. A cyst may develop beneath a blocked gland, but this does not increase your risk for breast cancer.

Hair Follicles: It is not unusual to have a few hairs growing on the surface of your areola or breast skin. If these are bothersome, carefully trim them - pulling them out with tweezers can be painful and may open the way to infections.

Sulcus: At the intersection of the areola and the rising edge of the nipple is a fold called the sulcus. It may be a smooth curve of skin, or it may look like a wrinkle. Inverted nipples may hide within the sulcus, while retracted nipples may pull in at the sulcus line.

Blood Circulation: Your nipples and areolas are connected to your blood supply by your axillary arteries. If you are having nipple-sparing breast surgery, the blood supply must be preserved to keep these tissues alive.

Muscles and Ligaments: Nipples are held erect by small, smooth muscles that respond to signals from your autonomic nervous system. Nipple erection can be caused by cold temperature or stimulation. Even though nipples can respond to sensual caresses, they are not considered sex organs.

Cooper's Ligaments form a hammock for your breast tissue to keep its shape - these run from tissue in your collarbone and chest wall throughout the breast and up to the areola skin.


Anatomy Of The Breast. Development of the Human Breast. Biology of the Mammary Gland. National Institutes of Health.

Proposed Classification of Pathology of human mammary gland. Dr.Sefton Wellings. Biology of the Mammary Gland. National Institutes of Health.

The Breast and It's Development. The Ductal Anatomy; Pp. 8- 11. Dr. Susan Love's Breast Book. Susan M. Love, M.D. Third Edition, 2000.

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  6. Breast Anatomy – Nipple and Areola Structure

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