212 



APPLIED ANATOMY. 



Laterally it is in relation with the left pleura above and the right below and the 

 vena azygos major runs along its right side posteriorly. The arch of the aorta winds 

 around its left side at the root of the lung. The right vagus nerve runs down pos- 

 teriorly and the left anteriorly, forming a plexus on its surface. 



Dilatation and Diverticula. In certain rare cases the 

 oesophagus becomes dilated ; this may involve the whole length 

 of the tube or only its lower end. Obstruction low down may be 

 a cause. It has been known to accompany a largely dilated aorta 

 which pressed the oesophagus against the diaphragmatic opening 

 and so hindered the passage of food. Regurgitation of food is a 

 prominent symptom and liquids may regurgitate from the stomach 

 and even enter the mouth. 



Diverticula are usually acquired and are but seldom con- 

 genital. The point of junction with the pharynx just behind the 

 cricoid cartilage is the most frequent seat. A sac is formed which 

 descends posteriorly behind the part of the tube below and as it 

 increases in size it presses forward and may obstruct its lumen. 

 Obstruction from foreign bodies, stricture, or disease of the cardiac 

 end of the stomach may be a cause. Vomiting is a prominent 

 symptom and the vomited material does not show any evidences of 

 digestion or the presence of acid. The existence of a tumor which 

 forms only on deglutition and which can be emptied by pressure 

 is said to be pathognomonic of an oesophageal diverticulum. 



Diverticula have been treated by washing out with a stomach- 

 tube, by excision, or if emaciation is rapid and marked by doing 

 a gastrostomy. 



Carcinoma and Stricture. Carcinoma is usually of a flat- 

 celled epitheliomatous type and may surround the oesophagus like 

 a ring. The walls are thickened, a tumor forms, and the internal 

 surface may become ulcerated. Stricture of the affected part may 

 lead to the formation of a dilation or diverticulum above, and ulcer- 

 ation and abscess may perforate and enter surrounding organs. 



Dyspnoea may arise from pressure on the air-passages and pus 

 may even penetrate them. Hemorrhage is also sometimes a symp- 

 tom. It may come either from the inside or outside. In the latter 

 case it may come from the large vessels in the neighborhood.. 



Septic inflammation may also be set up in the adjacent pleurae 

 and lungs. 



Foreign Bodies. Foreign bodies may become impacted 

 at any part of its course; this is particularly the case if they are 

 hard and rough with irregular outlines. If they are smooth and 

 soft and more or less rounded they are apt to lodge at the con- 

 stricted parts of the tube. These points are, as already stated, at 

 its commencement, where it crosses the aorta and left bronchus, 

 and where it passes through the diaphragm. The upper con- 

 striction is 1.5 cm. (or f in.) in diameter, and is least distensible. 

 It will dilate to the width of 2 cm., and thus will allow a body of 

 about |4 mcn diameter to pass. The two lower constrictions are 

 more distensible and a body that passes the oesophagus can usually 

 pass the ileocaecal valve, so that the upper end of the oesophagus 

 acts as a gauge to prevent the entrance of substances too large for 

 the rest of the alimentary tract. The bodies which become lodged 

 are usually those which have been pushed down beyond the open- 

 ing of the oesophagus by the contraction of the muscles of the 

 pharynx, and then on account of their irregular form become 

 PIG. 22.^. The oesopha- caught by the contraction of the tube below. With the head mod- 



gus. From a plaster cast. t i i i /- -n i / / \ r 



erately extended, the nrst constriction will be 15 cm. (6 in.) from 

 the teeth. A foreign body at this point will be opposite the cricoid cartilage at the 

 level of the sixth cervical vertebra. 



