kyynärluulle

Kyynärluu, scientifically known as the ulna, is one of the two long bones in the forearm of the human body. It is located on the medial side of the forearm, parallel to the radius, which is on the lateral side. The ulna is the larger of the two bones and articulates with the humerus at the elbow joint, forming the primary bone of the elbow. Its proximal end features the olecranon, a prominent process that forms the point of the elbow and serves as the insertion point for the triceps brachii muscle.

At the distal end, the ulna articulates with the radius and the carpal bones of the wrist. The head of the ulna is a small, rounded structure that fits into a notch on the distal radius. This articulation allows for pronation and supination of the forearm, the movements that turn the palm downwards and upwards, respectively. The interosseous membrane, a fibrous sheet of connective tissue, runs between the shafts of the ulna and radius, providing stability to the forearm and serving as an attachment point for muscles. The ulna plays a crucial role in supporting the weight of the body during activities like pushing and lifting, and it is essential for the overall function and mobility of the upper limb.