Mammary glands

Mammary glands are the organs that, in the female mammal, produce milk for the sustenance of the young. These exocrine glands are enlarged and modified sweat glands and are the characteristic of mammals which gave the class its name.

Anatomy

The basic components of the mammary gland are the alveoli (hollow cavities, a few millimetres large) lined with milk-secreting epithelial cells and surrounded by myoepithelial cells. These alveoli join up to form groups known as lobules, and each lobule has a lactiferous duct that drains into openings in the nipple.

Function

The primary function of mammary glands is to nurture young by producing breast milk. The milk is produced in the alveoli and is then pushed out through the lactiferous ducts towards the nipple where it is discharged. This process is known as lactation.

Development

The development of mammary glands is regulated by hormones. The mammary glands exist in both sexes, but they are rudimentary until puberty when, in response to ovarian hormones, they begin to develop in the female.

Clinical significance

Mammary glands are susceptible to numerous disorders, the most common of which is breast cancer. Other conditions include mastitis, fibroadenoma, and galactorrhea.

See also

• Breast
• Breastfeeding
• Lactation
• Milk