Humerus

SkeletalSkeletonArmLeft and right

View left in 3D View right in 3D

What it is

The upper-arm bone: a hemispherical head facing the glenoid, greater and lesser tubercles with the bicipital groove between, a cylindrical shaft with the deltoid tuberosity, and a flattened lower end bearing the trochlea, capitulum and epicondyles.

Function

Transmits forces between shoulder and elbow and anchors the deltoid, rotator cuff, biceps, brachialis and triceps.

Size

≈ 32 cm long; head radius 21 mm; shaft ≈ 22 mm wide

Clinical note

The ulnar nerve runs behind the medial epicondyle (the "funny bone"); mid-shaft fractures can injure the radial nerve in its spiral groove.