Which hormone is primarily responsible for breast development?

• A. Prolactin
• B. Testosterone
• C. Estrogen
• D. Luteinizing hormone

Answer: (C)

Estrogen is primarily responsible for breast development due to its critical role in stimulating the growth and differentiation of breast tissue, particularly during puberty and pregnancy. During puberty, the increase in estrogen levels leads to the development of ductal structures in the breast, the deposition of fat in breast tissue, and the overall enlargement of the breasts. Estrogen also works synergistically with other hormones, such as progesterone and prolactin, to promote further maturation of breast tissue, especially in preparation for lactation.

Prolactin, while important for milk production, plays a secondary role in the development of breast tissue itself. Testosterone does not contribute to breast development; rather, it is more involved in male reproductive characteristics. Luteinizing hormone primarily regulates the menstrual cycle and ovulation and does not directly influence breast development. Thus, the action of estrogen in promoting primary and secondary sexual characteristics in females is fundamental to breast development.