288 THE TISSUES. 



Nor can the nerves detected in it be regarded as belonging to it, 

 since they proceed beyond to terminate. Consequently, it mani- 

 fests but a slight degree of sensibility when divided by the sur- 

 geon's knife. The vessels in areolar tissue are generally arranged 

 so as to include hexagonal spaces, as seen in Fig. 183, from 

 Queckett ; and which also shows the appearance of the nerves. 



Uses of Areolar Tissue. 



The functions of areolar tissue depend on the physical properties 

 just mentioned. 



1. It isolates the various organs by constituting their external 

 envelop. 



2. It at the same time lies between and connects the various 

 organs together in the body, and yet so as to allow of a certain 

 amount of motion of one upon another. It is, therefore, the true 

 connective tissue (p. 275). 



3. It protects the proper substance or parenchyma of various 

 organs. 



4. It gives support to organs, and maintains them in their place. 

 Thus, with few exceptions, it accompanies the bloodvessels and 

 nerves to their minutest subdivisions. 



It must, therefore, be regarded as a subordinate tissue, wherever 

 found, though quite indispensable on account of the mechanical 

 uses just described. 



Distribution of the Areolar Tissue. 



The areolar is more extensively diffused than any other tissue in 

 the body. Indeed, it enters to such an extent into the structure of 

 every part and organ, with very few exceptions, that if all the other 

 tissues were entirely removed from the body, its conformation would 

 still be preserved in every part by the areolar tissue ; and, except 

 from the removal of the osseous and the muscular tissues, its weight 

 would be but slightly diminished, as the following particulars will 

 show: 



1. It surrounds and supports the arteries and veins everywhere, 

 and sometimes the capillaries also, and thus enters with the vessels 

 into every organ. 



2. It also forms sheaths (perineuria) around all the nerves ; 

 accompanying them, however, to their finest ramifications, in an 

 undeveloped form (p. 276). The brain, however, does not contain 



