100 NORMAL HISTOLOGY. 



CHAPTEE XIII. 



MEMBRANES AND GLANDS. 

 I. MEMBRANES. 



Membranes are disposed upon surfaces in the interior of the body. 



OUTLINE OF MEMBRANES. 



f Serous membranes proper. 



I 

 Serous membranes -{ Synovial membranes. 



Endothelium. 

 Epithelium. 



Mucous membranes 



Basement membrane. 



( Fibrous connective tissue. 

 Stroma .......... <J 



t Elastic fibers. 

 Muscular is mucosee. 



p .-,, 



(_ Occasional structures ....... <J Glands. 



{ Lymphoid cells. 



There are two kinds of membranes serous and mucous. Serous 

 membranes cover the outside surfaces of the alimentary tract and 

 respiratory organs, as well as the articular ends of bones and other 

 structures. They include three varieties serous membranes proper, 

 synovial membranes, and endothelium. Serous membranes proper 

 are composed of fibrous tissue and elastic fibres, with a superficial 

 layer of endothelium. Synovial membranes include the capsules 

 which envelop the ends of joints and the sheaths in which tendons 

 glide. They are characterized by the viscid fluid the synovia 

 which they secrete. Endothelium consists of a single layer of flat- 

 tened endothelial cells. 



Mucous membranes line all surfaces which are directly or indi- 

 rectly in communication with the external atmosphere. The struc- 

 ture of the mucous membrane exhibits the following elements: 

 (1) The epithelium. This may be simple or stratified. It may be 

 squamous, columnar, or ciliated. Columnar and ciliated epithelia 



