So you think you're familiar with these?
Well, what if we give you an illustrated version of a boob cut in half?
Chest wallPectoralis majoraDiaphragmBreastfeeding muscles
This is the chest wall!
The chest wall, also called the thorax, includes the ribcage, diaphragm, muscles, and joints which provide structural support, like an anchor, for the breast. They also protect the internal organs of the chest, like the lungs and heart.
DiaphragmLabia minoraPectoralis musclesFatty tissue
These are the pectoralis muscles!
The pectoralis major is the layer of muscle between the breast and the chest wall — also known as "pecs." The female breast itself does not have any muscles. It is actually super important in reconstructive and cosmetic breast surgery, because it acts as a barrier between the implant and the rest of the breast to reduce the risk of infection and allow for breastfeeding.
LobulesMilk ductsLymph nodesFatty tissue
These are the lobules!
The lobules of the breast are a bunch of glands that hold tiny sacs that produce milk, clustered together so they look like a bunch of grapes. The breast has millions of lobules, and these are drained of milk during breastfeeding.
Lactiferous ductCowper's glandNipple surfaceAlveoli opening
This is the surface of the nipple!
The nipple is the ending point of a network of tubes and ducts which drain milk from the lobules during breastfeeding. It's the external structure at the very tip of the breast, and it's filled with nerve endings, so it can be soft or hard in response to arousal, temperature, pain, etc.
AreolaLactation ductEndometrium layerAlveoli
This is the areola!
The areola is the dark pigmented circle of skin around the nipple on the center of the breast. They are thicker and sturdier than the rest of the delicate breast skin, so they help to prevent tears, cracking, and infections, especially during breastfeeding. They usually get bigger and darker during puberty and pregnancy in women. Areolas come in all different sizes, shapes, and colors — and they're all beautiful!
NodulesBartholin ductsLactiferous ductsLymphatic tubules
These are lactiferous ducts!
The lactiferous ducts carry milk from the full lobules to the nipple during breastfeeding. They are the connection between the inner glands of the breast and the external opening of the nipple. These can also occasionally become clogged and infected, causing inflammation of the mammary glands (mastitis) in the breast.
Lymphatic tissueMammary sacsNodesFatty tissue
This is the fatty tissue!
The space around the lobules and ducts is filled with fatty tissue, which includes fat, connective tissue, and ligaments. Fatty tissue grows during puberty to increase the size of the breasts. And this tissue is actually sensitive to changes in hormones, which is why breasts can change in size during the menstrual cycle and pregnancy. The amount of fatty tissue varies greatly in each woman, but all breast sizes are beautiful!
SkinAreola minoraLymphatic tissueEndometrium layer
This is the skin of the breast!
The skin of the breast holds the inner tissues of the breast tightly together to maintain the shape and structure of the external breast. This skin is meant to stretch during puberty to accommodate the growing fatty tissue and lobules. It's sensitive and delicate. Many women have stretch marks on the skin of their breasts due to rapid breast growth during puberty or pregnancy.
Lymph nodesRibsMilk production glandsMontgomery glands
These are the ribs!
The ribs lie under the pectoralis muscles and make up the bony structure of the chest wall, which anchors and supports the breasts. The ribs are also a skeletal protection for the lungs and chest cavity. They can become a bit strained during pregnancy due to excess pressure and volume in the abdomen.
These are the capillaries!
The capillaries are thin, fragile blood vessels in the breast. They carry blood full of oxygen and other nutrients from the arteries to all the tissues of the breast.
Anatomical definitions and information sourced in part by: