The Importance of Breast Anatomy

Half of the world has female breasts; yet, many women are not familiar with the anatomy of their own breasts. Whether breasts are large or small, these are essential parts that define femininity, represent sensuality, and have the capacity to nourish. This blog is written to help women understand the anatomy of the breast. After reading this, women should have a better understanding of the terminology, functions and structures of the breast. Of note, the medical jargon has been largely removed so that this article can be enjoyable for every reader.

Starting from a larger picture, each breast mound is bordered by the sternum (otherwise known as breastbone) and on the sides, by the armpit/chest regions. The bottom of the breast is called the inframammary fold. Deep to the breast is a paired, fan-like muscle called the pectoralis major muscle. We should not forget that deep to the breasts is the ribcage. The formation of the ribcage can affect the appearance of breasts as well. For example, if there is a concavity in the breastbone (ie. Pectus excavatum), the woman will have more cleavage. If the breastbone protrudes out more (ie. Pectus carinatum), the woman will have less cleavage and the breasts appear further apart.

The breast is covered by skin and a layer of fat called subcutaneous fat. Both the skin and fat can stretch, thin, and become weaker after pregnancies and breastfeeding. When we gain and lose weight, the changes are seen in the subcutaneous fat layer and in the fat distributed throughout the breast itself. The gland is made of breast lobes and breast ducts. There are fifteen to twenty glands called lobes, each of which have many smaller lobules that produce milk. These small lobules are arranged in clusters. There are also fibrous tissue and bands of ligaments that hold the breast tissue in place. One particular type, called Cooper’s ligaments, extend from the chest wall to the skin of the breasts and have a part in preserving breast youthfulness.

Breast ducts are thin tubes that transport the milk from the lobules to the nipples. Of note, breast cancers can form in the breast lobes and ducts. The nipples are made of a thin layer of muscle fibers and located in the middle of areolas. It is possible to have nipple piercings and still breastfeed; however, it is unpredictable how scar tissue from piercings could negatively impact breastfeeding. Some women are born without one or both nipples, a condition called athelia. Alternatively, amazia is where there is the presence of nipples, but not breast mounds. Lastly, there is a condition named amastia, where a women is born without breast mounds, nipples or areolas.

Areolas are the darker colored parts of skin that surround the nipple. In some women, the border of the areolas are distinct, meaning, they are clearly defined. In others, the areola pigment blends into the normal breast skin. Areolas typically are larger in women with larger breasts as weight of the gland descend into the areola and stretches it. Located in the areolas are specialized glands called Montgomery glands. These provide lubrication to the nipple to protect it during breastfeeding.

Towards the upper outer part of the breast and near the axilla, there is an extension of breast tissue named the Axillary Tail of Spence. When performing a breast examination, it is important to include this portion as breast cancer can be found here as well. When oncologic surgeons are removing breast tissue in mastectomies, they are careful to include this breast tissue.

Lymph nodes are small organs that produce immune fluid, called lymph, and are found throughout the body. This immune fluid is clear and circulates through our entire bodies. Lymph nodes help fight infection and cancer. Clusters of lymph nodes are located around the sternum, in the axillas, in the neck and around the collarbone. When we are sick, these lymph nodes can enlarge. Have you ever been ill and felt swollen around your throat or ears? Those are lymph nodes!

We hope that this blog topic helped your understanding of breast anatomy. Make sure you read our other blogs topics on breast examination and breast health!

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