The breast
Breast · mamma
Mostly fat and supporting tissue, built around the glands that can make milk.
What it does
Each breast sits on the chest muscles, over the ribs. Most of its volume is fat, held in shape by bands of tissue called suspensory ligaments that run from the chest wall to the skin. In the middle sits the nipple, surrounded by the darker areola, whose small bumps release oils that protect the skin. Hidden inside are the milk glands and ducts.
Surprising fact
Breast size depends mainly on the amount of fat, not on the milk glands, so it has little to do with how much milk a breast can make.
Why it matters
Breasts change through life with hormones: at puberty, through the monthly cycle, in pregnancy and after menopause. Knowing what is normal for you helps you notice changes early.
Nearby
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Sources
Drafted with AI help; awaiting a human fact-check against these sources.
Open in the 3D atlas · Suggest a correction · Not medical advice.
3D models: Z-Anatomy & BodyParts3D (CC BY-SA 4.0 / 2.1 JP). Card text CC BY 4.0.