THE (ESOPHAGUS. 



THE OESOPHAGUS. 



The oesophagus begins at the lower edge of the cricoid cartilage, opposite the 

 lower border of the sixth cervical vertebra, and ends at the cardiac opening of the 

 stomach, opposite the eleventh thoracic vertebra. 



It is 25 cm. (10 in.) long and begins 15 cm. (6 in.) distant from the teeth. In 

 the neck it inclines to the left, hence oesophagotomy is performed on that side. It 

 reaches the farthest point to the left at the level of the top of the sternum or oppo- 

 site the second thoracic vertebra. It then inclines to the right, reaching the median 

 line opposite the fifth thoracic vertebra. It then again inclines to the left, to pierce 

 the diaphragm in front of the aortic opening and to the left of the median line opposite 

 the tenth thoracic vertebra, and ends in the cardiac opening of the stomach entirely 

 to the left of the median line and opposite the eleventh thoracic vertebra or tenth 

 dorsal spine. In its passage through the diaphragm it is accompanied by the con- 

 tinuation of the two vagi nerves. At its termination it grooves the posterior surface 

 of the liver. 



Lumen. The lumen of the oesophagus is narrowed at three points, (i) its com- 

 mencement; (2) where it crosses the aorta and left bronchus; and (3) near its end 

 as it passes through the diaphragm. 



The average diameter of the lumen is 2 cm., which at the upper and lower 

 constrictions is reduced to 1.5 cm. The middle constriction is not quite so marked. 

 The lower constriction is most marked at the point of the passage of the oesophagus 

 through the diaphragm; it enlarges slightly as it enters the stomach. This part of 

 the oesophagus is quite distensible. The next most distensible part is opposite the 

 left bronchus. This is on a level with the middle of the first piece of the sternum and 

 the third thoracic vertebra. The upper constriction at the cricoid cartilage is the 

 least distensible part of the tube, so that a body passing it may pass entirely down. 



In both living and dead bodies the lumen of the oesophagus is sometimes open 

 and sometimes closed. In the neck the pressure of the soft parts usually keeps it 

 closed, but frozen sections of the dead body show it sometimes closed and sometimes 

 open. Mikulicz in using the oesophagoscope has found the lumen open in the living 

 patient and been able to see down the remainder of the tube when the instrument has 

 only been passed beyond the second constriction. 



In passing an cesophageal bougie, one should not be used of a larger diameter 

 than 1 8 mm. (^ in.). It will enter the oesophagus opposite the lower border of the 

 cricoid cartilage about 15 cm. (6 in.) from the teeth. It will pass the second con- 

 striction 7 cm. (2^4 in.) farther on, opposite the middle of the first piece of the 

 sternum or 2.5 cm. (i in.) below its upper border, and meet the third constriction 

 15 cm. (6 in. ) lower down, or 37 cm. (14.4 in. ) from the teeth, and enter the stomach 

 3 cm. below, or 40 cm. (16 inches) from the teeth and opposite the eleventh dorsal 

 vertebra. 



Relations. In the neck the oesophagus rests on the longus colli muscle and 

 vertebrae behind and has the trachea in front. On the left side it lies close to the 

 carotid sheath, the lobe of the thyroid gland, and the thoracic duct. The left recurrent 

 laryngeal nerve is in closer relation to it than the right on account of the latter 

 coming over from the right subclavian artery. The left nerve lies on its anterior 

 surface near the left edge. The right carotid artery lies farther from it than does 

 the left. The left inferior thyroid artery is also in closer relation to it than the right 

 on account of the inclination of the oesophagus to the left side. 



In the thorax it passes through the superior mediastinum between the trachea and 

 its bifurcation in front and the aorta behind. 



In front it has the bifurcation of the trachea and encroaches more on the left 

 than on the right bronchus. The arch of the aorta and the left carotid and subclavian 

 arteries also pass in front of it and in the posterior mediastinum the pericardium and 

 diaphragm are anterior to it. 



Posteriorly, above it rests on the spinal column, but below the bifurcation of 

 the trachea the aorta intervenes. 



