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THE ANATOMY OF THE HORSE 



POSTERO-EXTERNAL SCAPULAR REGION 



Triceps extensor brachii (caput magnum) is situated upon the infero- 

 posterior part of the shoulder, occupying the angular interspace between 

 the scapula and humerus. Origin— ivom the whole length of the posterior 



Fio. (^.—Internal View or the Muscles of the Shoulder and Arm. 



a. o. Cartilage at the base of the scapula. 



1. Insertion of serratus magnus turned up. 



2. Insertion of rhomboideus longus. 



3. Insertion of rhomboideus brevis. 



4. 5. Subscapularis. 



C. Teres internus vel m.ijor. 



7. Insertion of latissinms dorsi. 



8. Triceps extensor bracliii (caput magnum). 



0. Coraeo humeralis. 



10. Insertion of pectoralis. 



11. Flexor brachii. 



12. Triceps extensor brachii (oapnt tertinm). 



13. Extensor metacarpi magnus. 



14. Flexor metacarpi internus. 



15. Flexor metacarpi medius. 



border as high up as the supero-posterior angle of the scapula. Insertion — 

 to the inner and upper part of the olecranon. Action — to approximate the 

 scapula and humerus, and thus raise the elbow joint ; if the former is fixed, 

 to extend the arm. 



Triceps extensor brachii (caput medium) lies upon the infero-external 

 part of the shoulder and humerus. Origin — from the humerus, just behind 



