THE THORAX. 343 



carotid, and ascend in the interval between the trachea and 

 the oesophagus into the neck, q. v. t page 104. 



DISSECTION. 



If the innominate veins have been tied off, proceed with the following (if 

 they have not, then tie them off close to the superior vena cava) : 



Divide the branches of the aorta (or if they have been cut away in the 

 neck, remove the attached portions with the aortic arch), divide the trachea 

 at the opening of the chest, the phrenic, pneumogastric, and the recurrent 

 (left) laryngeal nerves. Lift everything forward and cut the aorta across at 

 the beginning of its downward curve. Separate the trachea from the oesoph- 

 agus, divide the azygos major close to the superior cava, sever the attachments 

 of the pericardium to the diaphragm, divide the inferior vena cava, and re- 

 move the heart, great vessels, adherent portions of nerves and veins, and the 

 trachea and lungs from the thoracic cavity. 



Place these parts into a common salt solution for later dissection. 



Turn to the interior of the thorax. 



The CEsophag-us. See page 124. Diags. 20 to 23. 



Begins in front of the fifth cervical vertebra and behind 

 the cricoid cartilage, nearly in the median line. It enters 

 the upper opening of the chest a little to the left of the 

 middle line and in front of the bodies of the vertebra, de- 

 scends to the cesophageal opening in the diaphragm, and 

 terminates in the stomach. In its course the thoracic duct 

 intervenes between it and the bodies of the vertebrae above 

 and the thoracic aorta below. Its length is from nine to 

 eleven inches. 



Relations. In the neck : In front, trachea. Laterally, 

 the lobes of the thyroid gland, the recurrent laryngeal 

 nerves, common carotid and inferior thyroid arteries, thor- 

 acic duct (at the left). Behind, prevertebral fascia, longus 

 colli muscle, lower cervical vertebrae (below the fifth). 



In the thorax : In front, trachea, left common carotid 

 and subclavian arteries, left bronchus, transverse aorta, 

 pericardium, left pneumogastric nerve. Laterally, pneu- 



