The ulna (ulna) is the long tubular bone of the forearm. Located medially (on the inside) of the radius. Its proximal end forms the olecranon process and part of the elbow joint. The distal end bears the styloid process and participates in the formation of the wrist joint.
The ulna bone performs supporting and protective functions, and is also the site of attachment of the forearm muscles. The shape resembles a triangular prism with rounded edges. It has a body and two ends - proximal and distal.