Special Histology and Embryology: A Practical Course - V. K. Napkhanyuk 2001

Skin and Its Appendages
Mammary Glands

The mammary gland (mammae) is embryologically a modified sweat gland of the Skin.

In a mature woman, each mammary gland consists of 15–20 individual glands separated by layers of loose connective and adipose tissue. Structurally, these are compound alveolar glands whose excretory ducts open at the apex of the nipple. The excretory ducts lead into dilated lactiferous sinuses (sinus lactiferi), which serve as reservoirs for milk accumulation. Opening into the lactiferous sinuses are numerous branching and anastomosing lactiferous ducts (ductus lactiferi) that terminate before Lactation as fine, blind-ending tubules known as alveolar lactiferous ducts (ductuli alveolares lactiferi), which give rise to numerous alveoli during Pregnancy and lactation.

Milk production takes place in the alveoli, which appear as rounded or slightly elongated sacs. The glandular Cells of the alveoli (lactocytes) are joined by tight junctions and desmosomes, forming a single layer on the basement membrane. The apical surface of the lactocytes features small microvilli. In some places at the Base of the lactocytes, basket-like (myoepithelial) cells can be found, embracing the exterior of the alveolus with their processes.



Last update: 10/08/2026

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