OPEBATIOHS ON THE (ESOPHAGUS. 



365 



Fia. 362.— Anatemy of the CEaophagUB and Jugular Vein of the Horse. J J, Jugular 

 vein; C, carotid artery; O H, sub-scapulo hyoideu3 muscle; D, oBsophagus ; S, sterno- 

 maxillaris muscle ; M, maBtoido-humeralla muscle. 



The relations of the oesophagus must then be considered accord- 

 ing to its divisions of the cervical, thoracic and abdominal portion. 

 At its point of origin, at the pharynx, it is situated between the 

 larynx and the guttural pouches. In the upper half of the neck it 

 is in relation, in. front, with the trachea; behind, with the long 

 muscle of the neck; and on the side with the car tid and its 

 sateUite nerves. Below this point, and as it deviates to the left, 

 it is related to the left side of the trachea, upon which it rests, 

 and on its outside, with the scalenus muscle, the carotid artery and 

 the jugular vein. In a very few instances, instead of passing to 

 the left of the trachea, it deviates to the right, but otherwise holds 

 the same relations as when in its normal position. At its entrance 

 into the thorax, the oesophagus, still on the side of the trachea, 

 corresponds outwardly with the inferior cervical gangHon and its 

 branches, and to the vertebral, superior cervical and dorsal arteries 



