THE GSOPHAGUS. 989 
it has rather the appearance of a solid 
muscular rod or band than of a bollow 
tube. 
The cesophagus presents two distinet con- 
strictions, one situated at its beginning, the 
other at the point where it is crossed by the 
left bronchus. Both constrictions are of 
the same size, and will admit without injury 
an instrument with a maximum diameter 
of 4 inch (20 mm.). At each of these points 
the tube is flattened from before backwards. 
The cesophagus varies in length in different 
individuals, from 8 to 14 inches (20 to 35 mm.). 
The distance from the upper incisors to the be- 
ginning of the esophagus 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 
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 dorsal vertebra. The 
second inchnation to this side begins about the 
seventh dorsal vertebra, and continues to the end of 
the csophagus, being considerably increased as the 
diaphragm is approached. 
Relations of the Csophagus. — The 
relations (Fig. 666) differ so widely in the 
neck and thorax that they must be described 
separately for each of these regions. 3 
In the neck.—J/n front lies the trachea— 
to the posterior membranous wall of which 
the cesophagus is loosely connected by 
areolar tissue—and in the groove at each 
side, between the two, the recurrent laryn- 
geal nerve ascends to the larynx (Fig. 666, A). 
Behind lie the vertebral column and the 
longus colli muscles, from which the ceso- 
phagus is separated by the prevertebral layer 
of the cervical fascia. At the sides are placed 
the carotid sheaths with their contained 
vessels, and the lateral lobes of the thyroid 
body. Owing to the deviation of the tube 
to the left in the lower part of the neck, its 
relation to the carotid sheath and thyroid 
body 1s much more intimate on this than 
on the right side. 
In the thorax.—The cesophagus passes 
successively through the superior and pos- 
terior mediastina, in the former lying close 
to the vertebral column, but in the latter 
advancing somewhat into the thoracic cavity 
and coming into contact with the back of 
the pericardium. The trachea still lies in 
front as far as its bifurcation. Immediately 
= 
Fig. A is at level 
of the upper 
part Ist dorsal 
vertebra, and 
shows the chief 
relations of the 
cesophagus in 
the neck and 
also its diver- 
gence to the 
left. 
Fig. B, at the 3rd 
dorsal verte- 
B bra, shows the 
thoracic duet 
lying on left 
side of the ceso- 
phagus. 
In Fig. C, at the 
level of the 5th 
dorsal vertebra, 
the left bron- 
chus is seen in 
relation to the 
front of the 
cesophagus. 
Fig. D is at level 
of 8th dorsal 
vertebra, and 
shows the peri- 
cardium lying 
on front of ceso- 
phagus. 
eet WO PD.) 
8™ DORSAL V. 
Fig. E, at 9th 
dorsal vertebra, 
shows the ceso- 
phagus inclin- 
ing to the left 
just before 
piercing the 
diaphragm. 
Fic. 666.—TRACINGS FROM FROZEN SECTIONS TO 
SHOW THE RELATIONS OF THE CESOPHAGUS 
at the levels of the Ist, 3rd, 5th, 8th, and 
9th dorsal vertebre 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 ; Of, 
(Esophagus; P, Pleura; Pe, Pericardiuin; R.B, 
Right bronchus; R.R, Right recurrent nerve ; 
R.V, Right vagus; T, Trachea; T.D, Thoracic 
duct; V.A, Vena azygos major. 
