When does breast development begin?
Breasts begin to form during fetal development, with a thickening in the chest area called the mammary ridge or milk line. By the time a baby girl is born, a nipple and the beginnings of the milk duct system have formed.
- Breast changes continue to occur throughout your life, with lobes, or small subdivisions of breast tissue, developing first.
- Mammary glands develop next, and consist of 15-24 lobes. Mammary glands are influenced by hormones activated by puberty.
- Involution of shrinkage of milk ducts is the final change that occurs within the breast tissue. Involution typically begins around the age of 35.
What breast changes happen at puberty?
As a girl approaches adolescence, the first outward signs of breast development begin to appear.
When the ovaries start to secrete estrogen, fat in the connective tissue begins to accumulate causing your breasts to enlarge. The duct system also begins to grow. usually, the onset of these breast changes is also accompanied by the appearance of pubic hair and hair under your
Once ovulation and menstruation begin, your breasts begin to mature and form secretory glands at the end of the milk ducts. Your breasts and duct system continue to grow and mature with the development of many glands and lobules.
The rate at which breasts grow varies greatly and is different for each young woman.
What changes happen to my breasts during menstruation?
Each month, women experience fluctuations in hormones that make up the normal menstrual cycle.
Estrogen, which is produced by the ovaries in the first half of the menstrual cycle, stimulates the growth of milk ducts in your breasts. The increasing level of estrogen leads to ovulation halfway through the cycle, and then the hormone progesterone takes over in the second half of the cycle, stimulating the formation of the milk glands.
These hormones are believed to be responsible for the cyclical changes such as the swelling, pain, and tenderness that many women experience in their breasts just before menstruation. During menstruation, many women also experience changes in breast texture, with breasts feeling particularly lumpy. These are the glands in the breast enlarging to prepare for a possible pregnancy. If pregnancy does not occur, the breasts return to normal size.
Once menstruation begins, the cycle begins again.