The humerus

This upper arm bone articulates proximally with the scapula and distally at the elbow with the radius and ulna. The proximal end is expanded into a head which articulates with the glenoid cavity of the scapula.

By Anatomography – en:Anatomography (setting page of this image), CC BY-SA 2.1 jp, https://commons.wikimedia.org/w/index.php?curid=23389521

Characteristics

Visit this AnatomyZone site to view the humerus in 3D. Observe the characteristics listed below while using the arrows to scroll through the info panel.

·  greater tubercle (lateral) and the lesser tubercle (anterior):two prominent points of muscle attachment

·  intertubercular sulcus (or groove):runs between the two tubercles

·  deltoid tuberosity:  a roughened raised ridge along the upper lateral side; it is the attachment site of the deltoid muscle. Rotate the humerus around to determine whether the deltoid tuberosity is lateral or medial. Use the thumbs and the lateral/medial epicondyles as your guides.

·  olecranon fossa: at distal end, on posterior aspect, depression to accommodate olecranon of ulna

·  capitulum: rounded, at the lateral distal end; articulates with the radius and

·  trochlea: at medial distal end, articulates with the ulna 

·  lateral and medial epicondyles: two prominent processes, at the sides

  • medial epicondyle: the conspicuous blunt projection felt on the medial side of the extended relaxed elbow.  The ulnar nerve runs across the posterior surface of this epicondyle and sharp pressure on this nerve against the epicondyle results in the feeling of “hitting your funny bone”.