Final answer:
Breasts are accessory organs of the female reproductive system involved in lactation and comprised of mammary glands and fat, playing a crucial role in infant nourishment with milk that is nutrient and antibody-rich.
Step-by-step explanation:
The breasts are accessory organs of the female reproductive system, primarily involved in supplying milk to an infant, a process known as lactation. They are composed of mammary glands and fat, and are not directly involved in reproduction. However, they play a crucial role in nourishing the infant post-birth. The mammary glands are comprised of 15 to 25 lobes with ducts leading to the nipple, which facilitate the transfer of milk. This milk is rich in nutrients and antibodies, essential for the infant's development and protection.
During pregnancy and lactation, the mammary glands undergo changes due to hormones such as estrogen and progesterone, enlarging and branching to prepare for milk production and secretion. The areola, containing Montgomery glands, secretes oils to maintain the health of the nipple during breastfeeding. While not being a question about enhancing or reducing the size of the breasts through surgical procedures such as skin grafts or implants, it's imperative to understand the anatomical and functional aspects of the breast in the context of human biology and medicine.