Head
- Has a smooth, rounded, articular surface and articulates with the scapula at the glenohumeral joint.
Anatomic neck
- Is an indentation distal to the head of the humerus and provides for the attachment of the fibrous joint capsule.
Greater tubercle
- Lies just lateral to the anatomic neck and provides attachments for the supraspinatus, infraspinatus, and teres minor muscles.
Lesser tubercle
- Lies on the anterior medial side of the humerus, just distal to the anatomic neck, and provides an insertion for the subscapularis muscle.
Intertubercular (bicipital) groove
- Lies between the greater and lesser tubercles, lodges the tendon of the long head of the biceps brachii muscle, and is bridged by the transverse humeral ligament , which restrains the tendon of the biceps brachii long head.
- Provides insertions for the pectoralis major on its lateral lip , the teres major on its medial lip , and the latissimus dorsi on its floor.
Surgical neck
- Is a narrow area distal to the tubercles that is a common site of fracture and is in contact with the axillary nerve and the posterior humeral circumflex artery.
Deltoid tuberosity
- Is a V-shaped roughened area on the lateral aspect of the midshaft that marks the insertion of the deltoid muscle.
Spiral groove
- Contains the radial nerve, separating the origin of the lateral head of the triceps above and the origin of the medial head below.
Trochlea
- Is the medial articular surface, shaped like a spool, and articulates with the trochlear notch of the ulna.
Capitulum
- Is the lateral articular surface, globular in shape, and articulates with the head of the radius.
Olecranon fossa
- Is a posterior depression above the trochlea of the humerus that houses the olecranon of the ulna on full extension of the forearm.
Coronoid fossa
- Is an anterior depression above the trochlea of the humerus that accommodates the coronoid process of the ulna on flexion of the elbow.
Radial fossa
- Is an anterior depression above the capitulum that is occupied by the head of the radius during full flexion of the elbow joint.
Lateral epicondyle
- Projects from the capitulum and provides the origin of the supinator and extensor muscles of the forearm.
Medial epicondyle
- Projects from the trochlea and has a groove on the back for the ulnar nerve and superior ulnar collateral artery.
- Provides attachment sites for the ulnar collateral ligament, the pronator teres, and the common tendon of the forearm flexor muscles.
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