Under breast development means the before the usually puberty under the influence of increasing estrogen -Spiegels occurring, slowly and continuously running development of the female breast . The beginning of this development, which occurs nowadays from the age of eight or nine, is referred to in science as thelarche .
In girls , the ovaries begin to slowly and continuously secrete estrogens even before puberty as the gonadotropin concentration in the blood increases . Under the influence of the increasing production and release of estrogen, the general growth of the mammary glands (Mamma, -ae; Latin: Glandula mammaria ) starts and at the same time a gradual, differentiating further development of these glands. In addition, the estrogens mediate the growth of the nipples ( nipples , lat. Papilla mammaria ) and the areola (lat. Areola ), furthermore the pigmentation of the nipples and their erectability .
At the same time, the rise in estrogen also triggers the onset of maturation of the uterus and vagina . The development of female proportions and the regulation of menstrual cycles are also dependent on estrogens. On the other hand, androgens are also produced in smaller quantities in the adrenal glands of girls (compared to estrogens) and released into the blood, which stimulate length growth and the formation of pubic hair and are later responsible for the appearance of armpit hair and possibly further body hair .
Stages of development
According to James M. Tanner , five stages are distinguished in the development of the female breast :
- B1: Breasts are still flat, the nipple is only a very small elevation.
- B2: The real puberty begins, mammary glands and adipose tissue begin to form the breast.
- B3: The nipple turns dark.
- B4: The border of the nipple, the areola , forms its own elevation.
- B5: The border swells again, but in some women it remains.
In stages 1 to 4, the breast increases, the adipose tissue increases. Breast development begins on average at 11 years of age and is completed at around 15, but the process can continue until the age of 19.
Advice centers recommend not to worry too much about too slow or too rapid breast development. On the one hand, a change in the breast does not reliably indicate pregnancy ; on the other hand, the final shape of the breasts is largely hereditary. Apart from a surgical procedure ( breast enlargement or possibly also breast reduction ), the shape of the breast can be regulated more or less by the body fat content, depending on the genetic condition.
- Erwin J. Haeberle : The sexuality of humans. de Gruyter, Berlin / New York 1983, ISBN 3-11-008753-7 .
- Wolf D. Keidel : Brief textbook of physiology. 2nd Edition. Thieme, Stuttgart 1970.