22 THE SURGICAL ANATOMY OF THE HORSE 



Under the longus colli is the trachea, interiorly to which are the 

 sterno-thyro-hyoideus, sterno-maxillaris and panniculus muscles. The 

 last-named muscle leaves the outer aspect of the sterno-maxillaris, and 

 spreads upwards over the jugular vein. 



Wedged in hetween the vein and the trachea at this point is 

 the carotid artery, which is at a slightly higher level than the vein. 

 On the superior aspect of the artery is the vagus nerve, which on 

 the left side is related superiorly to the oesophagus, and on the right 

 to the inferior border of the scalenus muscle. 



On the inferior aspect of the carotid, and between it and the 

 sterno-thyro-hyoideus muscle is the recurrent laryngeal branch of the 

 vagus. 



