MYOLOGY. 67 



(B) Sterno-prescapularis. 



Origin. — Sides of inferior border of sternum, and cartilages of 

 first three or four ribs. 



Insertion. — Supra-spinatus fascia. 



Action. — Pulls scapula backward and downward. 



Nerve. — Sixth and seventh cervical. 



ANTEA SPINATUS. 



Origin. — Ante-spinous fossa. 



Insertion. — By two tendons into external and internal humeral 

 tubercles. 



Action. — Extensor of humerus. 

 Nerve. — Sixth and seventh cervical. 



POSTEA SPINATUS. 



Origin. — Postea-spinous fossa, acromion spine and tuberosity. 

 Insertion. — External humeral tuberosity. 

 Actioji. — Abductor and external rotator. 

 Nerve. — Sixth and seventh cervical. 



TERES MAJOR. 



Origin. — One head from dorsal angle and the other from 

 aponeurosis and tuberosity of spine of scapula. 

 Insertio7i. — Deltoid imprint of humerus. 

 Action. — Abductor and external rotator. 

 Nerve. — Eighth cervical. 



TERES MINOR. 



Origin. — Posterior border and postea spinous fossa of scapula 

 and margin of glenoid cavity. 



Insertion. — Humerus between external and deltoid tuberosities. 

 Action. — Like preceding. 

 Nerve. — Circumflex. 



SUBSCAPULARIS. 



Oi'igin. — Subscapular fossa. 

 Insertion. — Internal tubercle of humerus. 

 Action. — Adductor and internal rotator. 

 Nerve. — Seventh cervical. 



