Supinator crest

Ulna
An example of standard anatomical position, with the ulna shown in red.
Details
Identifiers
Latin	Ulna
MeSH	A02.835.232.087.090.850
Dorlands /Elsevier	u_01/12835497
TA	A02.4.06.001
FMA	23466
Anatomical terms of bone []

The ulna (/ˈʌlnə/) is a long bone found in the forearm that stretches from the elbow to the smallest finger, and when in anatomical position, is found on the medial side of the forearm. It runs parallel to the radius, the other long bone in the forearm, and is the larger and longer of the two.

The bone may break due to excessive weight or impact.

The ulna is a long bone found in the forearm that stretches from the elbow to the smallest finger, and when in anatomical position, is found on the medial side of the forearm. It is broader close to the elbow, and narrows as it approaches the wrist.

Close to the elbow, the ulna has a bony process, the olecranon process, a hook-like structure that fits into the olecranon fossa of the humerus. This prevents hyperextension and forms a hinge joint with the trochlea of the humerus. There is also a radial notch for the head of the radius, and the ulnar tuberosity to which muscles attach.

Close to the wrist, the ulna has a styloid process.

Near the elbow, the ulna has two curved processes, the olecranon and the coronoid process; and two concave, articular cavities, the semilunar and radial notches.