01 / Location & anatomical relationships
On the thumb side of the forearm when the palm faces forward.
02 / Structure & organization
The radius has a disc-shaped proximal head and a broader distal end contributing substantially to the wrist. It articulates with the ulna proximally and distally. The interosseous membrane links the shafts.
03 / Function
It lies on the thumb side when your palms face forward.
04 / Mechanism
The radius joins the humerus near the elbow and helps form the wrist at its lower end. It can rotate around the ulna to turn the palm. That motion is useful for turning a page or holding a bowl.
Part of a bigger picture
The radius 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
Forearm rotation moves the radius around the ulna. In anatomical position, the radius is lateral, on the thumb side.
Check your understanding
Locate the radius 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.