Humerus

The humerus is the only bone of the skeleton of the arm (thoracic stylopodium).

It is composed by three basic segments:

• The proximal extremity, articulating with the scapula and bearing the head and the major and lesser tubercles

• The body (shaft) bearing the deltoid tuberosity

• The distal extremity bearing the humeral condyle and articulating with the radius and ulna

Variation:

• In the cat, the humerus resembles that of the dog, but it is curved only in its proximal quarter and becomes straight along the rest of its length. The coronoid fossa is shallow and does not communicate with the olecranon fossa, whereas the radial fossa is more marked than in the dog. Distally, a supracondylar foramen is present on the medial surface.