The growth and development of breast is mainly influenced by many hormones in reproductive endocrine shafting, such as gonadotropin and prolactin secreted by pituitary gland, estrogen and progesterone secreted by ovary; In addition, hormones secreted by adrenal gland and thyroid gland and growth hormone secreted by pituitary gland are needed to make breast development full and perfect.
If the function and regulation of the above organs, glands and hormone levels are disturbed, it will affect the development of the breast. The problem of mammary gland is not an isolated phenomenon, it is one of the manifestations of the whole secondary sexual characteristics, so it must be analyzed together with other secondary sexual characteristics when judging whether the mammary gland is developing normally. If other sexual characteristics are normal, but the breasts are not developed, it is probably a problem of the breasts themselves, such as the breast is not sensitive to the above hormones, or the level of a particular hormone is abnormal. If the whole secondary sexual characteristics are not well developed, then you need to go to the hospital for a serious examination.
Breast development will also be affected by genetic factors, nutrition, climatic conditions and environment, and doctors should consider these factors before making judgments and handling.
Girls are very concerned about the development of breasts, some worry that they develop too early, and some worry that they develop too late. When girls' breasts begin to develop, there are great individual differences. Some girls start to develop breasts when they are only 8 or 9 years old, and some girls don't start to develop until 16 years old or later. Most girls begin to develop breasts at the age of 9- 14.
In the development process, the mammary gland and its surrounding adipose tissue form a button-like protuberance on the nipple and its surrounding areola, which makes the nipple bulge bigger, then gradually becomes full, and finally develops into the shape of an adult breast. For girls, not only the age at which breasts begin to develop varies from person to person, but also the speed at which breasts develop. Some girls' breasts develop later, but faster; And some girls' breasts develop earlier, but slowly.
Girls with early breast development are often embarrassed by this, so they will deliberately hide their breasts; In order to cover up the early development of breasts, some walk with their heads down, cover their chests, or wear tights to tie their chests, which limits the normal development of breasts and breasts. The practice of chest restraint will oppress the breast, make the nipple sunken, and the breast will be stunted, which will make it difficult to breastfeed and lactation in the future, and it is also easy to cause breast diseases.
In essence, girls with big breasts are also influenced by many factors. Some girls are obese, which leads to fuller breasts, while others are influenced by genetic factors, nutritional conditions and climate.
Contrary to girls whose breasts develop earlier and bigger, some girls worry that their breasts develop later. More sensitive girls, in public toilets or group activities, it is easy to find that their breasts are not as plump as some peers. They doubt whether their breasts are developing normally, and they may also worry that their future fertility will be affected.
The size of breast development is not only influenced by estrogen in the body, but also by heredity, environmental factors, nutritional status, obesity, physical exercise and other factors. If the mother's breasts are smaller, most daughters are smaller, which is the role of genetic factors; It is also difficult for thin girls to have full breasts. Small breasts may also be related to development sooner or later. Although the breasts are small, as long as the development of reproductive organs and menstruation are normal, it will not affect the breastfeeding function and fertility of adults. Generally speaking, the development of breasts in the morning and evening does not affect the speed of their future development, nor does it affect the size and shape of breasts after adulthood, so girls with later and smaller breasts do not have to worry.
How do teenagers develop breasts?
Breast development is the first information of adolescent girls. The physiological function of breast is to secrete milk and feed babies, but its aesthetic significance often exceeds its physiological function.
Breast is evolved from sweat glands, which are breasts and fat covered by skin. Mammary gland is divided into acinus and mammary duct, which is surrounded by fat and fibrous connective tissue. There is a round nipple, about 4-5 cm in diameter, with sebaceous glands on it, which secrete sebum and moisten the nipple and nipple.
The development of young girls' breasts is mainly the extension and branching of mammary ducts, the increase of connective tissue elasticity and volume, and the accumulation of fat, while the full development of mammary vesicles secreting milk is after pregnancy. There is a fat bag all over the breast. When the fat layer is thick, the breasts will be full, plump and elastic.
In fact, people began to sprout breasts in the sixth week of embryo. By the time I was born, I had already started to have breasts.
In childhood, the breasts remain static, and there is not much difference between male and female breasts. However, until puberty, girls' breasts, like spring, are the first signal of development, from bud to bud, gradually plump and mature.
From the age of 9 to 10, the girl's ovaries begin to function, secreting female hormones, and then the breasts begin to develop. First, the nipple protrudes, then the breast enlarges, fat accumulates, and the whole breast develops completely.
Two or three years after the girl's breasts began to develop, she had menstrual cramps and pubic hair appeared six months later. As a result, a girl enters puberty and grows vigorously.
In girlhood, breasts are firm and elastic, because they are mainly mammary glands, but there is less fat; By the age of 20, the fat in the breast increases, forming a slightly drooping mature female breast. It takes about four or five years for a girl to develop from a breast to a basic shape.
The medical profession in China divides the degree of breast development of girls into four degrees: the first time the breast is flat, the breast has not yet developed; The second nipple and areola present bud-like protrusions on the chest wall; The third degree breast is slightly raised, and the nipple and areola protrude like hills on the breast; The fourth degree breast bulges obviously, the nipple protrudes, and the bud-like process disappears, becoming a mature breast.
According to the observation of children in Beijing, a few girls' breasts begin to develop at the age of 8, half at the age of 10, of which about 20% reach the third degree, all at the age of 13, more than 80% girls develop to the third degree, and 90% girls develop to the age of 19.
The development of female breasts is influenced by many factors, such as race, heredity, nutrition, region, cultural status and living habits. For various reasons, the development of young girls' breasts can be very different in the morning and evening. Some girls 13 years old began to develop, but they were immature at the age of 20, and even stayed at the third degree for the first time.
But the development of young girls' breasts began at the age of 1 1- 14. If a girl 15 years old or older, her breasts have not yet begun to develop, she should pay attention. If the breasts of 18 years old or older are not developed, it is necessary to consider whether it is caused by disease. For each situation, we should analyze it in detail.