Breast structure

Everyone's breasts have different structures. Some people have large breasts, while others have small breasts. Many people are more concerned about the shape and characteristics of their breasts. After entering puberty, the breasts begin to develop little by little. By the age of seventeen or eighteen, the breasts are fully developed. The physiological structure of the breast is very complex, containing multiple mammary ducts, which are completed by the densely packed structure of these mammary ducts.

Physiological structure of breast

There are 15 to 20 lactiferous ducts, arranged radially with the nipple as the center, converging at the areola and opening at the nipple, called the lactiferous foramen. The lactiferous duct is relatively narrow at the nipple, and then expands into an ampulla, called the lactiferous sinus, which has the function of storing milk. The opening of the mammary duct is composed of stratified squamous epithelial cells, the narrow part is composed of transitional epithelium, the ducts at all levels below the ampulla are composed of double-layer columnar epithelium or single-layer columnar epithelium, the terminal duct near the alveoli is composed of cuboidal epithelium, and the alveoli are lined with cuboidal epithelium.

The first stage of development (1 to 9 years old): Before puberty, breasts have not yet 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 appears as a distinct dome-shaped bulge.

Stage 3 (12-13 years old): The breasts become round and shaped like adults, but are still small.

Stage 4 (14-15 years old): The breasts enlarge rapidly, and the nipples and areola protrude forward, shaped like small balls.

Stage 5 (16-18 years old): Normal adult breasts are formed, and the small balls of the nipple and areola merge into the round shape of the breast.

Breast development

The time when women's breasts begin to develop varies depending on factors such as region and race. For most women, breast development begins between the ages of 8 and 13, and fully matures 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 development to full maturity.

Principles of Breast Development

The growth and development of the breasts are mainly affected by a variety of hormones in the reproductive endocrine axis, such as gonadotropin and prolactin secreted by the pituitary gland, and estrogen and progesterone secreted by the ovaries; in addition, the hormones secreted by the adrenal glands and thyroid glands, and growth hormone secreted by the pituitary gland are also needed for the breasts to develop fully and completely.

The size of breast development is affected not only by the effects of estrogen in the body, but also by genetics, environmental factors, nutritional conditions, obesity, physical exercise and other factors. If the mother has small breasts, her daughter will most likely have smaller breasts as well. This is due to genetic factors. It is also difficult for thin girls to have full breasts. Small breasts may also be related to the early or late development. Although the breasts are small, as long as the reproductive organs develop and menstruation are normal, it will not affect the breastfeeding function and fertility in adulthood. Generally speaking, the early or late development of breasts does not affect the speed of future development, nor does it affect the size and shape of the breasts in adulthood. The development of a girl's breasts is the first sign of the onset of puberty.