THE MUSCLES. 75 



MUSCLES SITUATED ON THE OS HUMERI. 



Biceps flexor cubiti arises from two heads, one from the coracoid 

 process, the other, called the long head, from the edge of the 

 glenoid cavity of the scapula. Inserted into the tuberosity at the 

 upper ei\d of the radius, at its fore part and a little below its neck. 

 Use To bend the fore^arm, which it does with with great strength, 

 and to assist the supinators. 



Brachialis internus arises from the os humeri at each side of the 

 tendon of the deltoides. Inserted into the coronoid process of the 

 ulna. Use To assist in bending the fore-arm. 



Triceps extensor cubiti arises from the neck of the scapula, and 

 the neck and middle of the humerus. Inserted into the upper and 

 outer part of the olecranon. Use To extend the fore-arm. 



Anconeus arises from the external condyle of the humerus. In- 

 serted into the back part of the ridge of the ulna. Use To assist 

 in extending the fore-arm. 



MUSCLES SITUATED ON THE FORE-ARM. 



Supinator radii longus arises from the external condyle of the 

 humerus. Inserted into the radius, near the styloid process. Use 

 To assist in turning up the palm of the hand. 



Extensor carpi radialis longior arises from the external condyle 

 of the humerus. Inserted into the metacarpal bone of the fore- 

 finger. Use To extend the wrist. 



Extensor carpi r.adialis brevior arises from the external condyle 

 of the humerus. Inserted into the metacarpal bone of the middle 

 finger. Use To assist the former. 



Extensor digitorum communis arises from the external condyle 

 of the os humeri. Inserted into the back of all the bones of the 

 fingers. Use To extend the fingers. 



Extensor minimi digiti arises from the outer condyle of the 

 humerus. Inserted into the second joint of the little finger. Use 

 To assist in extending the fingers. 



Extensor carpi ulnaris arises from the outer condyle of the os 

 humeri. Inserted into the metacarpal bone of the little finger. 

 Use To assist in extending the wrist. 



Flexor carpi ulnaris arises from the inner condyle of the humerus 

 and olecranon. Inserted into the os pisiforme, at its fore part. 

 Use to assist in bending the hand. 



Palmaris longus arises from the internal condyle of the os 



