All About Your Breasts
There are many misconceptions and myths about the breasts before pregnancy, during pregnancy and after pregnancy. Here's a look at some information about your breasts to dispel some of these misunderstandings. Find out how they change throughout your life including during ovulation, pregnancy and when you're breastfeeding.
The Scientific Stuff
Both men and women have breasts. When the baby is growing in utero, the same embryological tissues develop in the upper ventral region of the torso on both the right and the left sides. At puberty, spikes in the female sex hormone estrogen cause a woman's breasts to become more prominent. This does not happen in men because of the higher levels of testosterone.
Sometimes men have unusually high levels of estrogen which can cause them to develop enlarged breasts that make them look very woman-like. This condition is called gynecomastia and is most often seen in teenage boys and elderly men.
It's common for women's breast to be different sizes, especially when developing. During adulthood this size difference evens out and is not significantly large in most cases.
Breasts can vary is density, size, shape and position on a woman's chest. The shape is determined by the Cooper's ligaments, the suspensory ligaments that run from the clavical (collar bone) to the clavi-pectoral fascia (middle of chest).
The angle of the end of the breast is often angled, but rarely sharper than 60 degrees. It can also be flat at 180 degree angle. The breast itself is made out of sudoriferous (sweat) glands and fatty tissue. Each breast has a single nipple surrounded by an areola that can vary in color from pink to dark brown. The areola has several lubricating sebaceous glands and the breast itself contain mammary glands that produce milk under the right hormonal conditions. Two thirds of these glands are found within 30 millimeter of the base of the nipple. The milk is transferred outside the breast by ducts that drain into the nipple. The arrangement of the ducts doesn't follow a specific pattern and has been compared to the tangled roots of a tree. The ducts are not reservoirs for milk during breastfeeding. The mammary glands further in the breast are.
Blood supply to the breasts comes from the internal and lateral thoracic artery, the thoracoacromial artery and the posterior intercostals arteries. There is a large concentration of nerves and blood vessels in the nipples that makes them highly sensitive.
During puberty, a girl's body begins to produce estrogen which starts the maturation of her reproductive system and her breasts. As more estrogen is secreted by the pituitary gland, breasts continue to grow and eventually maintain their size throughout adulthood until pregnancy. (Excessive weight gain or weight loss will also increase or decrease breast size as the amount of fatty deposits change.) During breast size gets bigger because of estrogen secretion.
Hormonal changes during pregnancy increase the blood flow to the tissue very early which can cause them to feel tingly, sore and swollen. They often become more sensitive to the touch. Veins become more prominent because of this blood flow and your breasts will become larger as the mammary glands get bigger and prepare to produce milk. During the second trimester your breasts may start to leak colostrum, a sweet watery fluid that's also known as pre-milk. It's high in nutrients, will feed your baby for the first few days after birth, and may be discharged any time your nipples are stimulated. At first it'll look thick and yellow and closer to the birth it'll look pale and colorless.
Hormone changes cause the mammary glands to produce milk which pass through the ducts and are released in tiny openings in the nipples. Most women will produce milk within a week after giving birth regardless of whether or not they plan to breastfeed. The mammary glands continue to produce milk for as long as they're stimulated.