The Humerus is the major bone in the upper arm. It is the largest bone in the upper limb.
Its smooth, ball-like head (proximal end) articulates with the glenoid cavity of the scapula. Close to the head are the greater and lesser tubercles for the insersion of the muscles that surround and move the shoulder joint. The greater and lesser tubercles are seperated from each other by the intertubercular groove, in which lies the tendon of the long head of the biceps brachii muscle. The head is seperated from the tubercles by the anatomical neck. Distal to the anatomical neck is the surgical neck which is the most frequent fracture site of the proximal end of the humerus.
The distal end of the humorous connects through the elbow joint to the lower arm.