- The ulna is the medial bone of the forearm.
- The ulna articulates with:
- the humerus proximally, forming the elbow (humeroulnar) joint.
- the radius laterally, forming the three radioulnar joints.
- the carpals distally, forming the wrist joint.
NOTES:
- The ulna forms the principal articulation with the humerus at the elbow (humeroulnar) joint.
- The ulna is small and less functionally important at the wrist joint.
![Anterior view of the ulna and radius on the right side of the body.](https://learnmuscles.com/wp-content/uploads/2017/05/05-RU-anterior-5628-new-341x1024.jpg)
Anterior view of the ulna and radius on the right side of the body.
![Posterior view of the ulna and radius on the right side of the body.](https://learnmuscles.com/wp-content/uploads/2017/05/05-RU-posterior-6003-new-270x1024.jpg)
Posterior view of the ulna and radius on the right side of the body.
![Medial view of the ulna and radius on the right side of the body.](https://learnmuscles.com/wp-content/uploads/2017/05/05-RU-medial-5577-new-271x1024.jpg)
Medial view of the ulna and radius on the right side of the body.
![Lateral view of the ulna on the right side of the body. Note: The radius has been removed.](https://learnmuscles.com/wp-content/uploads/2017/05/05-U-lateral-5618-newer-1-205x1024.jpg)
Lateral view of the ulna on the right side of the body. Note: The radius has been removed.
![A proximal (superior) view of the ulna and radius on the right side of the body.](https://learnmuscles.com/wp-content/uploads/2017/05/05-RU-superior-6029.jpg)
A proximal (superior) view of the ulna and radius on the right side of the body.
![A distal (inferior) view of the ulna and radius on the right side of the body.](https://learnmuscles.com/wp-content/uploads/2017/05/05-RU-inferior-7222.jpg)
A distal (inferior) view of the ulna and radius on the right side of the body.