(ESOPHAGUS. 49 T 



of the back, that no very great regularity belongs to their 

 several attachments, a fact which explains the apparent 

 discrepancy among different authors. 



SECTION III. 

 ORGANS OF DEGLUTITION CESOPHAGUS. 



The oesophagus, (own/, to bear, $ a y?> food,) or food duct, 

 is a continuation of the pharynx, and, as its name implies, 

 is designed to convey our food and drinks from the mouth 

 and pharynx downward into the stomach. 



It commences at the lower portion of the pharynx, op- 

 posite the fifth cervical vertebra, and behind the cricoid 

 cartilage, at its lower border. It then descends the neck 

 nearly on the median line, lying first a little to the left 

 of this line in the neck, then inclining, as it enters the 

 chest, to the right; then again to the left, before it enters 

 the stomach. This flexuosity explains the occasional dif- 

 ficulty of introducing the probang. It passes behind the 

 trachea, the arch of the aorta, the pericardium, along the 

 posterior mediastinum, and in front of the thoracic aorta, 

 to the diaphragm, and terminates at the cardiac orifice of 

 the stomach, opposite the tenth dorsal vertebra. It is 

 made up of three distinct coats, with the blood-vessels and 

 nerves. The coats are the external, the middle, and the 

 internal, or muscular, cellular, and mucous. 



The muscular coat is composed of two very distinct planes 

 of fibres the external, running longitudinally, and the 

 internal, circularly, both being prolonged upon the stomach. 

 The cellular coat forms the connecting medium between the 

 muscular and mucous coats, and conducts the blood-vessels 

 and nerves to the latter. The mucous coat is pale, thin, 

 disposed in longitudinal folds, and covered by a delicate 

 epithelium or cuticle. It also contains mucous follicles, 

 sometimes called cesophageal glands, whose orifices are 

 seen in the depressions between the longitudinal folds. 



The arteries of the oasophagus come from the inferior 

 thyroid in the neck ; from the bronchial and aorta in the 

 chest ; and from the diaphragmatic and coronary artery of 

 32 



