50 ANATOMY IN A NUTSHELL 



LESSON X. 



Mus< i.i.-. There are seventeen muscles attached to the scapula. 

 Three to the vertebral border- Three to the fossae — 



Levator anguli scapulae; Supraspinatus — in the supraspinous 



Rhomboideus minor; fossa-; 



Ethomboideus major. Infraspinatus — in the infraspinous 



TWO L'O A( ROMION PRO< ESS — fossa; 



Trapezius;. Subscapularis— in the subscapular 



Deltoid. fossa. 



Three to the axillary bori>eh Three to the coracoid process — 

 Long head of the Triceps; Short head of Biceps; 



Teres minor: Coraco-brachialis ; 



Teres major. Pectoralis minor. 



Three irregularly arranged — 



Omo-hyoid, near transverse ligament; 



Serratus magnus, on the vertebral aspect of the venter; 



Latissimus dorsi, on the interim' angle, dorsal aspect. 



When all the muscles of the clavicle ami scapula are uiven. we have all the 

 muscles in the upper extremity as far as the elbow, except the Brachialis an- 

 ticus. (Plate XVI.) 



Pectoralis minor. — Description. — (Plate XVI.) — This is a thin. flat, tri- 

 angular muscle situated at the upper part of the thorax beneath the Pectoralis 

 major. Its upper border is separated from the clavicle by a triangular inter- 

 val, broad internally, narrow externally, which is occupied by the costo-cor- 

 acoid membrane. In this space is the first part of the axillary vessels ami 

 nerves. Running parallel to the lower border of the muscle is the long thoracic 

 artery. 



Origin. —Upper margin ami outer surface of the third, fourth and fifth 

 ribs near cartilages, and aponeurosis covering the Intercostal muscles. 



Insertion. The fillers converge and form a flat tendon which is inserted 

 into the inner horde!' and upper surface of the coracoid process of the scapula. 

 (Plate XXI.) 



Action.- To depress the point of the shoulder and aids in forced inspira- 

 tion. 



Nerve Si pply. -Internal anterior thoracic, the filaments being derived 

 from the eighth cervical and first dorsal nerves. 



Blood Supply is from the internal mammary, intercostals, superior thor- 

 acic, acromial thoracic, and long thoracic. 



Triceps. Description. (Plate XVIII.)— The Triceps is situated at the 

 hack of the arm. extending the entire length of the posterior surface of the 

 humerus. It is of large size and divided above into three parts, hence its name. 

 The-.- portions have been named (1) the middle, scapular, or long head; (2) 



