39 6 



HISTOLOGY. 



goblet cells. The tunica propria is well developed, being even 4 mm. 

 thick on the inferior concha. It consists of fibrillar tissue with many elastic 

 elements especially in its deeper layers. Beneath the epithelium it is thick- 

 ened to form a homogeneous membrana propria perforated with small holes. 

 Lymphocytes, are present in variable quantity, sometimes forming solitary 

 nodules and often entering the epithelium in great numbers. Branched 



Epithelium. 



Tunica 

 propria. 



. Vein. 



Mucous 

 cells. 



Serous 

 cells. 



'- 'f~\ '. &] ffSi ':''* *'**".' '\ -.-."'" '.'f N --^vV .'f\:L'~ 



. . - vV.-- V,- , "' : "" 



""'' ' ' 



.S>' (Mi^^^|Wv ; ' -' 

 & ^ fc^^?^^^^^te4^^^; 



. :Vw;v,^v--^,:'--:: N. -: :-^---..-.y:-- i; V , -v:. 



: -^ 



Artery. 



; Bone. 



FIG. 446. VERTICAL SECTION THROUGH THE MUCOSA OF THE INFERIOR CONCHA OP MAN. X 48. 

 On the left is a funnel-shaped depression receiving an excretory duct; nearby on the right is the 

 section of a large vein. 



alveolo-tubular mixed glands extend into the tunica propria. Their serous 

 portions have intercellular secretory capillaries. Both mucous and serous 

 cells contain a trophospongium. The glands often empty into funnel 

 shaped depressions which are macroscopic on the inferior concha, and 

 are lined with the superficial epithelium. The mucosa of the several 

 paranasal sinuses is thin ( 0.02 mm.), with less elastic tissue and but 



