DISSECTING MANUAL. 



MUSCLES. 

 Pectoral Group. 



Pectoralis Major. Origin; (clavicular portion) inner half, 

 or two-thirds, of front of clavicle; (costo-sternal portion) an- 

 terior surface of sternum, first six costal cartilages; (abdom- 

 inal portion) a separate slip from the aponeurosis of the 

 Obliquus externus. Course; it so twists on itself that the 

 lower fibres get behind the upper and are inserted higher on 

 the humerus. Insertion; outer border of bicipital groove of 

 humerus, extending to the great tuberosity and blending with 

 the insertion of the Deltoid and Latissimus dorsi; a band 

 ascends from this to the shoulder- joint capsule, enveloping the 

 Biceps tendon, and another descends to the fascia of the 

 arm. [322] 



Pectoralis Minor. Origin ; third, fourth, and fifth ribs an- 

 teriorly; fascia on third and fourth intercostal spaces. Inser- 

 tion; front of tip of coracoid process; (usually) conjoint origin 

 of Biceps and Coraco-brachialis. [324] 



Subclavius. Origin; upper surface of first costal cartilage 

 in front of costo-clavicular ligament. Insertion; groove in 

 middle third of under surface of clavicle. [324] 



Serratus Magnus. Origin; external aspect of upper eight 

 ribs, by fleshy slips; the first slip is double and attached to 

 the upper two ribs and intervening fascia. Insertion; (from 

 upper two ribs) ventral aspect of upper angle of scapula; (three 

 slips from second to fourth ribs) vertebral border of scapula; 

 (four slips from fifth to eighth ribs) ventral aspect of lower 

 angle of scapula. [325] 



Shoulder Group. 



Deltoid. Origin ; front of outer third of clavicle; outer bor- 

 der of acromion process; lower border of spine of scapula. 

 Course; the most anterior fibres are parallel; the intermediate 



[158] 



