<Tr> <Td_colspan="2"> Anatomical terminology (edit on Wikidata) </Td> </Tr> <P> In human anatomy, the arm is the part of the upper limb between the glenohumeral joint (shoulder joint) and the elbow joint . In common usage, the arm extends to the hand . It can be divided into the upper arm, which extends from the shoulder to the elbow, the forearm which extends from the elbow to the hand, and the hand . Anatomically the shoulder girdle with bones and corresponding muscles is by definition a part of the arm . The Latin term brachium may refer to either the arm as a whole or to the upper arm on its own . </P> <P> The humerus is one of the three long bones of the arm . It joins with the scapula at the shoulder joint and with the other long bones of the arm, the ulna and radius at the elbow joint . The elbow is the hinge joint between the end of the humerus and the ends of the radius and ulna . The humerus cannot be broken easily . Its strength allows it to handle loading up to 300 pounds (140 kg). </P> <P> The arm is divided by a fascial layer (known as lateral and medial intermuscular septa) separating the muscles into two osteofascial compartments: the anterior and the posterior compartments of the arm . The fascia merges with the periosteum (outer bone layer) of the humerus . The compartments contain muscles which are innervated by the same nerve and perform the same action . </P>

What are the two main bones in your arm
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