Breast Anatomy

    This article explains the functional anatomy of breasts, the development of breasts under hormonal control, and anatomical factors affecting lactation.


    Important Points

    breast anatomy
    Alveoli make and store breast milk. Oxytocin hormone squeezes alveoli to secrete this stored breast milk.
    • Milk is secreted and stored in alveoli.
    • Myoepithelial cells surround the alveoli and contract in response to oxytocin hormone ejecting the stored milk from alveoli to lactiferous ducts.
    • Lactiferous ducts transport this milk to nipples.
    • Estrogen and growth hormone stimulates growth of milk carrying ducts during pregnancy.
    • Progesterone, prolactin, and human placental lactogen stimulate alveolar growth during pregnancy.
    • Because of these changes during pregnancy: Breast increases twice in volume, visible superficial veins over breasts, areola enlarges and darkens, Montgomery tubercles protrude from areola, and some milk may start leaking during the second half of pregnancy.
    • A mother with hypoplastic breasts need intensive lactation support: Frequent breastfeeding and pumping; close watch on baby’s attachment, breastfeeding, and weight; and tube assisted supplementation if required.

    Posttest Quiz

    Breast Anatomy

    1 / 5

    About breast anatomy, which is false:

    2 / 5

    About alveoli, which of the following is false:

    3 / 5

    A woman with 18 weeks of pregnancy arrives at your Comprehensive Lactation Management Center (CLMC). She is worried that she will not be able to breastfeed her baby because of the small size of her breasts. On asking, she has not felt any changes in her breasts after the onset of pregnancy. All of the following is true regarding the management of women having hypoplastic breasts except:

    4 / 5

    All of the following are true about breast changes during pregnancy, except:

    5 / 5

    All are true regarding the development of breasts except:

    Your score is

    Related article: Breast Anatomy: Can it Affect Breastfeeding?


    1. Ramsay DT, Kent JC, Hartmann RA, Hartmann PE. Anatomy of the lactating human breast redefined with ultrasound imaging. J Anat. 2005;206(6):525-534. doi:10.1111/j.1469-7580.2005.00417.x
    2. J├╝tte J, Hohoff A, Sauerland C, Wiechmann D, Stamm T. In vivo assessment of number of milk duct orifices in lactating women and association with parameters in the mother and the infant. BMC Pregnancy Childbirth. 2014;14:124. Published 2014 Apr 2. doi:10.1186/1471-2393-14-124
    3. Love SM, Barsky SH. Anatomy of the nipple and breast ducts revisited. Cancer. 2004;101(9):1947-1957. doi:10.1002/cncr.20559
    4. von Heimburg D, Exner K, Kruft S, Lemperle G. The tuberous breast deformity: classification and treatment. Br J Plast Surg. 1996;49(6):339-345. doi:10.1016/s0007-1226(96)90000-4
    5. Neifert MR, Seacat JM, Jobe WE. Lactation failure due to insufficient glandular development of the breast. Pediatrics. 1985;76(5):823-828.
    6. Huggins KE, Petok ES, Mireles O. Markers of Lactation Insufficiency: A Study of 34 Mothers. Clinical Lactation 2000: 25-35.

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