Where Breast Milk Comes From and Flying with Breast Milk

flying with breast milk

Since the production of breast milk in order to feed infants is common across mammalian species, it can be easy to see breastfeeding as something completely mundane. Have you ever asked yourself how the body does it, though? How do the breasts “know” when to release milk, and what substances inside the human body are able to combine to form the perfect nutrition for newborns?


Creating breast milk is actually a complex and fascinating process. While many think of the breasts as organs or appendages, what they actually are is glands composed of multiple types of tissue, and these tissue types, as well as other body systems like nerves and blood, all have unique roles to play in breast milk production.


So there is blood in breast milk?
Well, sort of. Some of the components of blood end up in breast milk. The blood itself is more of a transportation system. It brings oxygen and nutrients from other parts of the body and deposits them in breast tissue. The tissue then provides these nutrients to the alveoli for breast milk production.


What kinds of breast tissue are involved, and what do they do?
Blood provides the transport, and breast tissue provides the storage and the “on” switch that tells the alveoli to start milk production.
Fatty tissue in the breasts is primarily a storage mechanism, while glandular tissue switches on milk production. It does this by producing hormones that tell the alveoli in the breasts to get to work.


How do the alveoli work?
The alveoli in the breasts respond to the hormone prolactin. This hormone signals the alveoli that it’s time to access the nutrients and oxygen stored in the surrounding tissue and create breast milk. Prolactin is produced as a standard part of the third trimester of pregnancy, but also in response to an infant’s suckling, which is how the breast “knows” to continue producing until an infant is done nursing.


How does the breast milk get to the infant?
Once the alveoli, which make up a cluster located near the back of the breast, produce breast milk, it is transported through milk ducts to the nipple, where it is secreted. This is where the nerves come in to the picture.
When the nerves in the breast are stimulated by suckling, it initiates what’s called the “let down reflex.” This reflex is what tells the milk ducts to send the breast milk to the infant. This reflex usually occurs shortly after suckling begins, and may happen repeatedly throughout a breast feeding session. Some women report a tingling sensation or mild discomfort when the let down reflex occurs, but others don’t feel this reflex at all.


If you have problems breast feeding
Even though the process of creating and secreting milk is natural and innate, it still requires practice for both the mother and the baby. Some women feel bad about themselves when they have breast feeding problems, but they absolutely should not.


There is also a possibility that another underlying condition could create pain or other breast feeding issues, and in most cases these problems are very treatable. Don’t hesitate to contact your OB/GYN or Nurse Midwife if you have problems producing milk or other breast feeding issues.

Going to be flying with breast milk? Check out milkful