

C. THE (ESOPHAGUS, BY E. KLEIN. 529 



In Man it is lined by laminated pavement epithelium, the 

 cells of which, both in their form and arrangement, resemble 

 those of the lower part of the pharynx. 



The membrana mucosa is situated between the muscular 

 layer of the mucous membrane which commences with the 

 oesophagus, and the epithelium, and it is separated by this 

 muscular layer from the thicker layer of the submucous tissue 

 which occupies the interval between the muscularis mucosse 

 and the muscularis externa. 



In newly born children* the mucosa exhibits in many parts 

 the structure of adenoid tissue. In others, again, numerous 

 bloodvessels are found, running for the most part in a longi- 

 tudinal direction beneath the epithelium, and accompanied by 

 a sparing amount of connective tissue derived from the external 

 portion of the mucous membrane. 



In adults the longitudinal fasciculi of connective tissue de- 

 rived from the submucosa run inwards between the fasciculi of 

 muscularis mucosse, and then either pursue a sinuous course 

 parallel to each other, or form plexuses. A great number of 

 cellular structures are constantly found amongst them. 



The surface of the mucous membrane is beset in adults with 

 a large number of conical papillae 0'3 0*5 of a millimeter in 

 length, which project into the epithelium; but in children 

 their presence is only indicated by slight inflections of the 

 line of attachment of the epithelium. 



The muscularis mucosse, or muscular layer of the mucous 

 membrane, consists of fasciculi of smooth muscular tissue run- 

 ning longitudinally, which are only feebly developed in the 

 uppermost part of the oesophagus, where they are separated 

 from one another by large quantities of the mucous tissue ; 

 lower down they become coarser and more closely approxi- 

 mated, so that the muscularis mucosse here forms a continuous 

 muscular layer. 



The septa of the several fasciculi are continuous with the mu- 

 cosa on the one hand and the submucous tissue on the other. 



* E. Klein, Ueber die Vertheilung der Muskeln des (Esophagus, etc^ 

 " On the arrangement of the Muscles of the (Esophagus ; " Sitzungsberichte 

 der k. k. Akad. der Wissenschaften zu Wien. Mai heft, 1868. 



