MAMMARY GLAND

PRERNA FOR IAS

MAMMARY GLAND

1. Definition of Mammary Gland

The mammary gland is a modified sweat gland found in female mammals that produces and secretes milk to nourish newborn babies after childbirth. It is an important part of the female reproductive system and becomes fully functional during pregnancy and lactation. Mammary glands are made up of glandular tissue, ducts, connective tissue, and fat. Milk produced by these glands supplies essential nutrients, antibodies, hormones, and growth factors needed for an infant’s growth and development. Besides providing nutrition, breastfeeding strengthens the immune system and promotes bonding between the mother and baby, making the mammary gland vital for newborn survival.

2. Structure of Mammary Gland

Each breast contains 15–20 lobes, which are further divided into many smaller lobules. Each lobule contains tiny sac-like structures called alveoli, where milk is produced. The alveoli are lined by secretory epithelial cells, responsible for synthesizing milk. Surrounding the alveoli are myoepithelial cells, which contract to push milk into the ducts. Milk flows from the alveoli through mammary tubules into mammary ducts, then to the mammary ampulla, lactiferous ducts, and finally exits through the nipple. Fatty tissue surrounds the gland, giving the breast its shape while also protecting the glandular structures.

3. Hormonal Control of Mammary Gland

The development and function of the mammary gland are controlled by several hormones. Estrogen stimulates the growth and branching of mammary ducts during puberty and pregnancy. Progesterone promotes the development of lobules and alveoli, preparing the breast for milk production. Prolactin, secreted by the anterior pituitary gland, stimulates the secretory epithelial cells of the alveoli to produce milk after childbirth. Oxytocin, released from the posterior pituitary gland, causes contraction of the myoepithelial cells around the alveoli, resulting in milk ejection, also known as the let-down reflex, during breastfeeding.

4. Estrogen

Estrogen is a female sex hormone produced mainly by the ovaries. It plays a major role in the growth and development of the mammary glands during puberty. Estrogen stimulates the formation and branching of the mammary ducts and increases fat deposition in the breast, contributing to breast enlargement. During pregnancy, estrogen works with progesterone to prepare the breasts for lactation. Although it promotes breast development, estrogen does not directly stimulate milk production. Proper estrogen levels are essential for normal reproductive health, breast maturation, and the maintenance of female secondary sexual characteristics throughout life.

5. Progesterone