Picture of small granules on the breast

An organ unique to humans and mammals that is used to feed milk. In humans, it is located in the 4th intercostal space on the midclavicular line, one above and one below. Normal children and boys have no obvious symptoms. Women grow up slowly during puberty due to the stimulation of estrogen. The breasts of adult women are hemispherical, the nipples are cylindrical, the skin in the center is dark red, and there are skin glands called nipples. The inside of the breast is mainly composed of 15 to 20 glandular (milk gland) lobules and fat tissue.

The glandular ducts are arranged radially, with the housing of the mammary ducts facing the nipple and opening at the nipple. During pregnancy and breastfeeding, the glandular ducts grow and develop most vigorously, the breasts become larger, protruding forward or sagging; the nipples expand and become darker in color, and enlarged veins can be seen on the surface of the breast skin. After menopause, the ovaries cease to function, breast volume and fat decrease, and are replaced by fibrous tissue.

Breast development:

Due to factors such as region and race, the time when women's breasts begin to grow and develop varies. For most women, breasts begin to grow and develop between the ages of 8 and 13, and are fully developed between the ages of 14 and 18. Breast development usually starts from the left side, and it takes about 3-5 years from the beginning of growth and development to complete maturity.

The first stage (1 to 9 years old): Before puberty, the breasts have not grown and developed.

The second stage (10-11 years old): In the early stage of breast development, the breast bud under the nipple begins to grow and develop, showing a prominent dome-shaped protrusion.

Stage 3 (12-13 years old): The breasts become rounder and shaped like those of adults, but are still smaller.

Stage 4 (14-15 years old): The breasts expand rapidly and the nipples protrude forward, becoming spherical in shape.

The fifth stage (16-18 years old): Normal adult breasts are formed, and the ball of the nipple is fused with the ring of the breast.