b4 DISSECTION OF THE NECK. 



serratus magnus muscle appears ; and behind the large cervical nerves, 

 towards the lower part of the space, is placed the middle scalenus muscle. 

 Through the scalenus issue two muscular nerves ; one, formed by two 

 roots, for the serratus magnus ; the other smaller, and higher up, for the 

 rhomboids!* 



Fig. 14. 



PART OF THE POSTERIOR TRIANGLE OF THE NECK is HERE DISPLAYED, 



but the student should carry the dissection as high as the head, so as to lay bare the whole of 

 that space. 



1. Stcrno-mastoideus. 

 '2 Trapezius. 



3. Posterior belly of the omo-hyoid muscle. 



4. Anterior scalenus, with the phrenic nerve 



on it. 

 .">. Middle scalenus muscle. 



6. Elevator of the angle of the scapula. 



7. Third part of the subclavian artery. 



8. External jugular vein joining the subchi- 



vian below. 



9. Nerves of the brachial plexus. 

 10. Spinal accessory nerve. 



(Blandin's Surgical Anatomy.) 



Limits of the space. The space is bounded in the front by the sterno- 

 mastoid muscle, l ; and behind by the trapezius, 2 . Its base corresponds 

 with the middle third of the clavicle, and its apex is at the skull. In its 



