THE (ESOPHAGUS. 



1151 



When seen in sections of the frozen 

 body (Fig. 908), the oesophagus usually 

 appears either as a flattened tube with a 

 transverse slit-like cavity, or as an oval or 

 rounded canal with a more or less stellate 

 lumen. The former condition is more 

 common in the neck, owing to the pressure 

 of the trachea, and the latter in the thorax. 



When exposed in the ordinary post- 

 mortem examination soon after death, it 

 has rather the appearance of a solid muscular 

 rod or band than of a hollow tube. 



The oesophagus presents three distinct 

 constrictions, one situated at its beginning, 

 another at the point where it is crossed by 

 the left bronchus, and the third where it 

 passes through the diaphragm. The two 

 upper constrictions are of the same size, 

 and will admit without injury an instru- 

 ment with a maximum diameter of -f- inch 

 (20 mm.). At each of these points the 

 tube is flattened from before backwards. 



The oesophagus varies in length in different 

 individuals, from 8 to 14 inches (20 to 35 cm.). 

 The distance from the upper incisors to the begin- 

 ning of the oesophagus averages about 6 inches 

 (15 cm.). 



During life the cervical portion is said, under 



' ordinary circumstances, to be closed and flattened 

 from before backwards by outside pressure, whilst 

 the thoracic portion may be open owing to the 



i negative pressure in the thorax. The passage into 

 the stomach is also said to be open (Mickulicz), but 

 this is doubtful. 



The size at the two constrictions, when the tube 

 is fully distended, is 23 mm. transversely, and 

 17 mm. antero-posteriorly. The other parts vary 

 in diameter between 26 and 30 mm. (Jonnesco). 



In its first curvature to the left the divergence 

 is greatest opposite the third thoracic vertebra. 

 The second inclination to the left begins about 



i the seventh thoracic vertebra, and continues to the 



: end of the oesophagus, being considerably increased 

 as the diaphragm is approached. 



Relations of the (Esophagus. The 

 relations (Fig. 908) differ so widely in the 

 neck and thorax that they must be described 

 ' separately for each of those regions. 



In the Neck. Anteriorly lies, the trachea 



-to the posterior membranous wall of 



which the oesophagus is loosely connected by 



'areolar tissue and in the groove at each 



side, between the trachea and oesophagus, 



the recurrent nerve ascends to the 



larynx (Fig. 908, A). Posteriorly lie the 



vertebral column and the longus colli 



'muscles, from which the oesophagus is 



separated by the prevertebral layer of the 



vical fascia. On each side are placed the 



carotid sheath with its contained vessels, and 



the corresponding lobe of the thyreoid gland 



and the inferior thyreoid artery. Owing 





Fig. A is at level 

 of the superior 

 part 1st thoracic 

 vertebra, and 

 shows the 'chief 

 relations of the 

 oesophagus in 

 the neck and 

 also its diver- 

 gence to the 

 left. 



|SJ THORACIC V. 



Fig. B, at the 3rd 

 thoracic verte- 

 bra, shows the 

 thoracic duct 

 lying on left 

 side of the oeso- 

 phagus. 



3 r . d THORACIC V. 



In Fig. C, at the 

 C level of the 5th 

 thoracic verte- 

 bra, the left 

 bronchus is seen 

 in relation to 

 the anterior sur- 

 face of the 

 oesophagus. 



Fig. D is at the 

 level of the 8th 

 thoracic verte- 

 bra, and shows 

 the pericardium 

 lying on the 

 anterior surface 

 of the oeso- 

 phagus. 



Fig. B, at the 9th 

 thoracic verte- 

 bra, shows the 

 oesophagus in- 

 clining to the 

 left just before 

 piercing the 

 diaphragm. 



THORACIC V. 



FIG. 908. TRACINGS FROM FROZEN SECTIONS TO 

 SHOW THE RELATIONS OF THE (ESOPHAGUS 

 at the levels of the 1st, 3rd, 5th, 8th, and 

 9th thoracic vertebrae, respectively. 



A, Aorta ; C, Common carotid artery ; D, Diaphragm ; 

 L.B, Left bronchus ; L.C, Left subclavian artery ; 

 L.R, Left recurrent nerve; L.V, Left vagus; OE, 

 (Esophagus; P, Pleura; PC, Pericardium; R.B, 

 Right bronchus ; R.R, Right recurrent nerve ; 

 R.V, Right vagus; T, Trachea; T.D, Thoracic 

 duct ; V.A, Vena azygos. 



