DISSECTING MANUAL. 



groove of humerus. A bursa separates its tendon from that 

 of the Teres major just before they fuse. [319] 



Arm Group. 



Coraco-brachialis. Origin; tip of coracoid process, con- 

 jointly with short head of Biceps. Insertion; impression at 

 middle of inner border of humerus. [332] 



Biceps. Origin; (short head) tip of coracoid process, with 

 preceding; (long head) supra-glenoid impression at root of 

 coracoid process, and glenoid ligament, by a long rounded ten- 

 don. Course ; the two bellies become united by fascia and join 

 a flat tendon. Insertion; rough posterior portion of bicipital 

 tubercle of radius ; deep fascia of forearm internally, by a mem- 

 branous band (semilunar, or bicipital fascia) derived from the 

 lower muscle fibres and the inner and anterior part of the 

 tendon. [332] 



Brachialis Anticus. Origin; lower two-thirds of front of 

 humerus, below Deltoid insertion ; both intermuscular septa. 

 Insertion ; inferior surface of ulnar coronoid process. [334] 



Triceps. Origin; (middle, long, or scapular head) axillary 

 border of scapula just below glenoid fossa; (outer head) outer 

 border of humerus from insertion of Teres minor to musculo- 

 spiral groove, external intermuscular septum; (inner head) 

 triangular area on back of humerus from insertion of Teres 

 major to olecranon fossa, both intermuscular septa. Course; 

 the heads join a broad, common tendon. Insertion; upper end 

 of olecranon process and deep fascia of forearm on either side 

 of it. [334] 



NERVES. 



Brachial Plexus. This is formed by the anterior primary 

 divisions of the lower four cervical nerves and most of the first 

 thoracic; it often receives a branch from the fourth cervical, 

 and sometimes one from the second thoracic which enters the 

 intercosto-humeral. It appears in the posterior triangle be- 



[160] 



