THE MUSCLES OF THE SHOULDER 301 
Relations.—Laterally, the subscapularis, the brachialis, the tendon of insertion 
of the latissimus dorsi, and the humerus; medially, the deep pectoral; in front, 
the biceps brachii. The anterior circumflex artery and the nerve to the biceps 
pass between the two parts, or between the muscle and the bone, and the brachial 
vessels lie along the posterior border of the muscle. 
Subscapularis 
Anterior deep pectoral 
Latissimus dorsi 
Teres major a : 
Supraspinatus 
Posterior deep 
pectoral 
Tensor fascie antibrachi 
Coraco-brachialis 
Biceps brachii 
Extensor carpi radialis 
n/ 4 Brachialis 
\ Ns - Long medial ligament of elbow 
Deep fascia of forearm — i; | 
a \ j 
y , 
Fic. 277.—Musc.ies oF SHOULDER AND ARM OF Horse; MEDIAL VIEW. 
1, Long head of triceps brachii; 2, medial head of triceps; 3, distal end of humerus. 
Blood-swpply.—Anterior circumflex artery. 
Nerve-supply.—Musculo-cutaneous nerve. 
4. Capsularis.'—This is a very small muscle, which lies on the flexion surface 
of the capsule of the shoulder joint. 
1 Also known as the scapulo-humeralis posticus s. gracilis. 
