The womb
Uterus · uterus
A hollow, muscular organ low in the pelvis where a baby grows during pregnancy.
What it does
The womb sits between the bladder and the rectum. Its thick wall is made of smooth muscle, and its lining thickens each month, ready for a fertilised egg. If no pregnancy starts, the lining is shed as a period. In pregnancy it holds and protects the growing baby, then its muscle squeezes hard to push the baby out during birth.
Surprising fact
In pregnancy the womb grows from about the size of a small pear until its top reaches the bottom of the ribs. Within about six weeks after birth it shrinks back to nearly its old size.
Why it matters
Period cramps are the womb's muscle contracting. The 3D model comes from a woman of 59, after menopause, so its womb is smaller than a younger woman's. The vagina is in the 3D model too; the vulva is part of the skin surface.
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.