Ulna

Definition

The ulna is one of the two long bones in the forearm, located on the side opposite the thumb and running parallel to the radius. It forms a major part of the elbow joint and articulates with the humerus at its larger end, known as the olecranon.

Related terms

Radius:

The radius is the other long bone in the forearm, positioned on the thumb's side and working in conjunction with the ulna to allow wrist movement.

Olecranon:

The olecranon is the prominent bony projection of the ulna at the elbow, which forms part of the elbow joint by fitting into a notch in the humerus.

Humerus:

The humerus is a long bone in the upper arm that articulates with both the radius and ulna at its distal end to form part of both elbow and shoulder joints