THE ESOPHAGUS 421 



palate to the level of hyoid bone. It opens into the oral cavity, 

 through the fauces, bounded on either side by the anterior 

 and posterior pillars, between which are the tonsils. 



The laryngeal part is continuous with the oral portion 

 above, and below at the level of the cricoid cartilage is con- 

 tinuous with the esophagus. Anteriorly, it presents the 

 aperture of the larynx, bounded in front by the epiglottis, 

 and laterally by the arytenoepiglottic folds. On either side of 

 the aperture is the sinus pyriformis, bounded internally by the 

 arytenoepiglottic folds and laterally by the thyroid cartilage 

 and thyrohyoid membrane. 



The pharynx is lined with mucous membrane continuous 

 with that lining the Eustachian tube, the nasal fossae, the 

 mouth, and the larynx. In the nasopharynx it is covered by 

 stratified ciliated epithelium; in the buccal and laryngeal 

 portions it is of the stratified squamous variety. 



The arteries are derived from the ascending pharyngeal, 

 ascending and descending palatine, the tonsillar. The veins 

 empty into the pharyngeal and facial plexuses. The lymphatics 

 drain into the retropharyngeal nodes in the retropharyngeal 

 space and the upper deep cervical nodes. 



THE ESOPHAGUS 



The esophagus is the tube connecting the pharynx with 

 the stomach, and extends from the level of the sixth cervical 

 vertebra through the diaphragm, entering the stomach oppo- 

 site the tenth or eleventh dorsal vertebra, a distance of 9 or 

 10 inches, and from the incisor teeth to the beginning of the 

 esophagus is about 6 inches; thus making the distance from 

 the incisor teeth to the cardiac opening of the stomach 15 to 

 16 inches. At first in the median line it runs to the left as 

 far as the root of the neck, becomes again mesial, and lastly 

 turns toward the left to pass through the esophageal orifice 

 in the diaphragm. It also corresponds to the cervical and 

 dorsal curves of the spine. It is the narrowest part of the 

 alimentary canal, and presents two constrictions, one at its 

 commencement, the other at the diaphragm. 



IN THE NECK it is in relation, in front, with the trachea; behind 

 with the longus colli and spinal column; laterally, with the 



