01 / Location & anatomical relationships
On the front of your abdomen.
02 / Structure & organization
The umbilicus marks the former attachment of the umbilical cord. After birth, cord vessels close and their remnants become associated with internal ligaments. The visible scar lies in the anterior abdominal wall rather than opening into the digestive tract.
03 / Function
Before birth, the umbilical cord connected your body to the placenta.
04 / Mechanism
Before birth, the umbilical cord attached here and carried blood between the developing baby and the placenta. After birth, the remaining cord dries and separates, leaving a scar. The shape of that scar varies.
Part of a bigger picture
The belly button belongs in our torso & skin collection. Explore the nearby parts to see how this area of the body fits together.
Explore torso & skin →FOR DEEPER STUDY
Connect structure with function
The fetal connection involved exchange through the placenta. An adult umbilicus is a surface landmark, not a working route for nutrition or breathing.
Check your understanding
Locate the belly button in relation to its neighbors. Explain how the structural features described above support its function, then distinguish it from a nearby structure with a different role.
Keep learning
Continue with OpenStax Anatomy and Physiology for system-level study. This atlas is educational and has not undergone independent medical peer review.