CBSE Class 12-science Answered

The human reproductive system includes primary and secondary organs which play an important role in reproduction. The primary reproductive organs are the organs responsible for producing the egg and the sperm cells (gametes), for producing hormones that function in the maturation of the reproductive system, for the development of sexual characteristics and for regulating the normal physiology of the reproductive system. All other organs in the reproductive system are considered secondary (or accessory) reproductive organs.  These are the ducts, and the glands that transport and sustain the gametes and nurture the developing offspring.

Mammary glands are considered to be accessory glands in females as they not directly involved in sexual reproduction but play an important role after the process of reproduction. They are made of modified sweat glands consisting of 15-25 lobes that radiate around and open at the nipple. The lobes contain glandular alveoli that produce milk in lactating women. The milk secreted by mammary glands is highly nutritious for the new-born baby. The activity of mammary glands is related to reproductive hormones-prolactin, oestrogen and progesterone, which are prominently secreted during pregnancy.