all that contains the lymph drainage system of
the posterior portion of the larynx, and it is largely by this route
that posteriorly located malignant laryngeal neoplasms early
metastasize to the mediastinum.

[58] [FIG 46.--Esophagoscopic and Gastroscopic Chart

BIRTH 1 yr. 3 yrs. 6 yrs. 10 yrs. 14 yrs.ADULTS
23 27 30 33 36 43 53 Cm. GREATER CURVATURE
18 20 22 25 27 34 40 Cm. CARDIA
19 21 23 24 25 31 36 Cm. HIATUS
13 15 16 18 20 24 27 Cm. LEFT BRONCHUS
12 14 15 16 17 21 23 Cm. AORTA
7 9 10 11 12 14 16 Cm. CRICOPHARYINGEUS
0 0 0 0 0 0 0 Cm. INCISORS
FIG. 46.--The author's esophagoscopic chart of approximate distances
of the esophageal narrowings from the upper incisor teeth, arranged
for convenient reference during esophagoscopy in the dorsally
recumbent patient.]

The lengths of the esophagus at different ages are shown
diagrammatically in Fig. 46. The diameter of the esophageal lumen
varies greatly with the elasticity of the esophageal walls; its
diameter at the four points of anatomical constriction is shown in the
following table:

Constriction Diameter Vertebra

Cricopharyngeal Transverse 23 mm. (1 in.) Sixth cervical
Antero-posterior 17 mm. (3/4 in.)
Aortic Transverse 24 mm. (1 in.) Fourth thoracic
Antero-posterior 19 mm. (3/4 in.)
Left-bronchial Transverse 23 mm. (1 in.) Fifth thoracic
Antero-posterior 17 mm. (3/4 in.)
Diaphragmatic Transverse 23 mm. (1 in+) Tenth thoracic
Antero-posterior 23 mm. (in.--)

For practical endoscopic purposes it is only necessary to remember
that in a normal esophagus, straight and rigid tubes of 7 mm. diameter
should pass freely in infants, and in adults, tubes of 10 mm.

The 4 demonstrable constrictions from above downward are at
1. The crico-pharyngeal fold.
2. The crossing of the aorta.
3. The crossing of the left bronchus.
4. The hiatus esophageus.
There is a definite fifth narrowing of the esophageal lumen not easily
demonstrated esophagoscopically and not seen during dissection, but
readily shown functionally by the fact that almost all foreign bodies
lodge at this point. This narrowing occurs at the superior