A girl's breasts get bigger during puberty due to the production of the hormone estrogen by the ovaries. This estrogen causes fat to collect in the connective tissue of the breasts, leading to their enlargement. The duct system within the breasts also starts to grow during this time.
Here's a breakdown of how this happens:
- Estrogen Production: As a girl approaches her teenage years, her ovaries begin producing and releasing estrogen.
- Fat Accumulation: The estrogen stimulates the growth of fat cells in the connective tissue of the breasts. This fat accumulation contributes to the increase in breast size.
- Duct System Development: The estrogen also promotes the growth of the duct system, which carries milk from the milk-producing glands to the nipple.
While breast size is primarily determined by genetics, it can also be influenced by factors like weight gain, as breasts contain fat cells.
It's important to remember that breast development can vary significantly from girl to girl, and some girls may experience breast growth before others. It's also normal for one breast to develop slightly faster than the other.
