322 



HEAD AND NECK 



trachea have already been fully discussed in connection with 

 the description of the parts occupying the middle line of the 

 neck (p. 229). Posteriorly^ it rests upon the gullet. Upon 

 either side is the common carotid artery whilst closely applied 

 to it in its upper part is the lateral lobe of the thyreoid 

 gland. The recurrent nerve ascends, on each side, in the 

 angle between the trachea and oesophagus. 



The oesophagus or gullet is a narrow tube, with thick 

 muscular walls, which extends from the pharynx to the 

 stomach. In the cervical part of its course it lies between the 

 trachea and the longus colli muscles, and as it descends 



Trachea 



Recurrent 



Common carotid artery 

 Internal jugular vein 



Thyreoid gland 

 Tfc ' Sterno-thyreoid 

 / Sterno-hyoid 



v?>^ Sterno-mastoid 



Vagus nerve 



iferior thyreoid artery ' 

 Vertebral vein 



S Vertebral artery '' GE sopriag us 



Longus colli 



S 



/I r 



' ''] ; ' A :'. 



ist dorsal vertebra 



** Recurrent n( 

 "- Vertebral vein 



FIG. 127. Transverse section through the Thyreoid Gland, Trachea, and 

 Gullet, at the level of the first Thoracic Vertebra. 



it inclines slightly to the left, so that it comes more closely 

 into relation with the lateral lobe of the thyreoid gland and 

 the carotid sheath upon the left side than with the same 

 structures on the opposite side. 



The dissector may terminate his dissection of the neck by 

 an examination of the scalene muscles, and the rectus capitis 

 lateralis. 



Musculi Scaleni. These muscles constitute the fleshy mass 

 which is seen extending from the transverse processes of the 

 cervical vertebrae to the upper two costal arches. They are 

 three in number, and are named, from their relative positions, 

 anterior, medius, and posterior. 



Musculus Scalenus Anterior. This is a well-defined muscle 

 which is separated from the scalenus medius by the roots of 



