44 LIGAMENTS AND MUSCLES OF THE HOESE. 



Insertion. — The tendon passes underneath the internal lateral 

 ligament of the elbow-joint, to be attached to the radius 

 and ulna. 



Action. — To flex the elbow-joint. 



POSTERIOR BRACHIAL REGION. 



1. Caput maynnia\ 



2. " medium r Triceps extensor hrachii. 



3. " parvum J 



4. Scajndo-ulnmns. 5. Anconeus, 



1. Caput magnum. 



Origin. — From the dorsal angle and posterior border of the 



scapula. 

 Insertion. — To the summit of the olecranon. 

 Action. — To extend the elbow and flex the shoulder. 



2. Caput medium. 



Origin. — From a rough line extending up from the deltoid 



ridge of the humerus. 

 Insertion. — To the olecranon. 

 Action. — To extend the elbow-joint. 



3. Caput parvum. 



Origin. — From the humerus below and behind the internal 



tubercle. 

 Insertion. — To the olecranon. 

 Action. — Same as preceding. 



4. SCAPULO-ULNARIS. 



Origin. — From the posterior border of the scapula. 



Insertion. — To the posterior border of the olecranon, and to 



the fascia of the fore-arm. 

 Action. — To extend the elbow-joint and tense the fascia of the 



fore-arm. 



5. Anconeus. 



Origin. — From the margin of the olecranon fossa 



