01 / Location & anatomical relationships
At the front of the knee, within the quadriceps tendon.
02 / Structure & organization
The patella is a sesamoid bone embedded in the quadriceps tendon. Its posterior articular surface glides against the femur. The patellar ligament continues from it toward the tibial tuberosity.
03 / Function
It protects the joint and helps your thigh muscles straighten your leg.
04 / Mechanism
The kneecap moves along a groove in the femur as the knee bends and straightens. It changes the angle of the tendon so the thigh muscles can pull effectively. Its position also shields the front of the joint.
Part of a bigger picture
The patella belongs in our bones & movement collection. Explore the nearby parts to see how this area of the body fits together.
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Connect structure with function
By holding the tendon farther from the knee's axis, the patella improves the extensor mechanism's leverage. Its movement follows the geometry of the femoral groove.
Check your understanding
Locate the patella 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.