3U 



A MANUAL OF ANATOMY 



and subsequently descends upon the axillary surface of the serratus 

 magnus, supplying branches to all its serrations. 



The Nerve to the Subelavius. — ^This small branch arises from the 

 front of the upper trunk, its fibres being derived from the fifth 

 cervical. It descends over the third part of the subclavian artery, 

 and, passing behind the clavicle, it enters the subelavius muscle 

 on its deep aspect. This nerve sometimes communicates with the 

 phrenic nerve. 



The Suprascapular Nerve. — ^This is a large nerve which arises 



To Cervical Plexus 1 



To Brachial Plexus^ 



4.C. 



Third Root of Phrenic (inconstant) 

 Nerve to the Rhomboids 

 Nerve to Subelavius \ 



Suprascapular \ 



External Anterior Thoracic 



Circumflex 

 Musculo-spiral 



Outer Root of Median 

 Musculo-cutaneous 



Median 



' Posterior Thoracic (Ext. 

 Respiratory N. of Bell). 

 First Intercostal 



i_ ■ Upper or Short Subscapular 

 \ \ "Internal Anterior Thoracic 

 ^. Middle or Long Subscapular 

 > Lower Subscapular 



\ Nerve of Wrisberg 



N Inner Root of Median 

 Internal Cutaneous 



'Ulnar 



Fig. 178. — The Brachial Plexus. 



VeJlow= Spinal Nerves and their Branches; Blue = Trunks; Red = Outer Cord ; 

 Purple = Inner Cord ; Grey = Posterior Cord . 



from the back of the upper trunk, its fibres being derived from the 

 fifth and sixth cervical. It is directed downwards, outwards, and 

 backwards beneath the trapezius and posterior belly of the omo- 

 hyoid to the upper border of the scapula, on approaching which it 

 gets in company with the suprascapular artery. It is distributed 

 to the supraspinatus, infraspinatus, and shoulder-joint. 



Infraclavicular Branches.— -Outer Cord. — The branches of this cord 

 are the external anterior thoracic, musculo-cutaneous, and outer 

 root of the median. 



The external anterior thoracic, which derives its fibres from the 



