Ulna
Ulna
- Latin synonym: Os ulnae; Os ulnaris
- Synonym: Ulnar bone
Definition
The ulna is a long bone, prismatic in form, placed at the medial side of the forearm, parallel with the radius. It is divisible into a body and two extremities. Its upper extremity, of great thickness and strength, forms a large part of the elbow-joint; the bone diminishes in size from above downward, its lower extremity being very small, and excluded from the wrist-joint by the interposition of an articular disk.