264 



Muscles of the Chest. 



M. subclaviiis 



C'lavicula 



M. trapezius 

 M. pectoralis minor 

 Processus coracoideus 

 Acromion 



M. sternocleidomastoideus 



M. deltoidcus 



subscapularis - 



M. coraco- 

 brachialis . 



\l. teres major 



ndon of in- 

 iertion of 

 he m. pec- 

 1 rails major 



M. biceps 



brachii 

 aput breve 



M. biceps 

 brachii 

 put longum) 



M. triceps 



brachii 

 iputlaterale) 



Costa I 



Sternum 



M. serratus anterior 



Mm. intercostales interni 



M. latissimus dorsi 



Costa V 



310. Muscles of the right side of the chest (2'"^ layer), 



viewed from in front. 

 (The platysnia and the ni. pectoralis major have been removed.) 



M. pectoralis miuor. Form: flat, oblong - triangular. Position: oii thr anterior 

 surface of the tliorax and (if th(> axilla, covered by the m. pectoralis major. Origin: by four 

 or three digitations from the anterior surface of the 2^'^ or S^'i 5''' rib. Insertion: the fibers 

 converge upward and lateralward to go by a short tendon to the proc. coracoideus scapulae. 

 Action: it draws the lateral angle of the scapula downward and forward; when the shoulder 

 blade is fixed it elevates the ribs to which it is attaclnMl. Innervation: nn. thoracales 

 anteriori's. 



M. subclavius. Form: flat-cyhndrical, narrow, short. Position: hidden between the 

 clavicle and the 1=** rib, covered by the platysma, the clavicle and the m. pectoralis major. 

 Origin: tendinous, from the anterior surface of tlie \^^ custal cartilage, just lateralward from the 

 lig. costodaviculare. Insertion: obliquely lateralward and upward to the inferior surface of the 

 clavicle. Action: it draws the clavicle downward and forwar<l. Innervation; n. subclavius. 



