72 NORMAL HISTOLOGY AND ORGANOGRAPHY. 



lum of interlacing fibrils and is found in adenoid 

 tissue, lymph nodes, spleen, and membrana propria 

 of mucous membranes. Also, to a limited extent, in 

 bone marrow. 



5. Areolar Connective Tissue. This is really a mix- 

 ture of interlacing bundles of white and yellow 

 elastic fibers. It is found subcutaneously to the 

 skin, to which it imparts elasticity. Areolar tissue 

 is vascular and favors, therefore, a rapid spread of 

 bacteria. Over bony prominences there is a limited 

 supply of areolar tissue and the skin at these places 



has restricted mobility. It 

 is at these points that the 

 spread of an infection, such 

 as erysipelas, is checked. 



General Considerations. 

 On account of the embry- 

 onic condition of connec- 

 tive-tissue cells these, like 



Fig. 41. Elastic fibers of the 



mesentery. epithelial cells, are fre- 



quently met with in patho- 

 logical tumors. If the tumor is malignant it is 

 called a sarcoma, and is as fatal to life as carcinoma, 

 or cancer. If the tumor is made up largely of fat 

 cells, it is called a lipoma, and if the fibrous elements 

 predominate it is a fibroma. 



The production of connective tissue is often 

 nature's method of checking the spread of a disease. 

 This tissue is produced as a wall in advance of a 

 spreading infection, and if the bacteria are unable to 

 penetrate this barrier, the disease soon becomes self- 

 limiting. This accounts for the swollen infected 



