CONNECTIVE TISSUE 



61 



FIG. 71. TRANSECTION OF A FASCIC- 

 ULUS OF THE LlGAMENTUM NUCH^B 



OF THE Ox, SHOWING THE VERY 

 LARGE ELASTIC FIBERS EMBEDDED 

 IN A VERY DELICATE NETWORK OF 

 COLLAGENOUS FlBERS. 



Picro-fuchsin. X 550. 



with the elastic fihers of the other 

 types of connective tissue. 



The elastic fibers are bound to- 

 gether by delicate sheaths of very fine 

 collagenous fibers, and are united into 

 bundles by coarser bands of fibrous 

 tissue. Elastic tissue is found in the 

 ligamenta flava, the stylohyoid liga- 

 ment and in the ligamentum nuchaB 

 (Svhitleather') of quadrupeds. In 

 these locations it occurs in consider- 

 able quantity and has a peculiar yel- 

 lowish color ; it is for this reason that 

 it is frequently described as yellow 

 elastic tissue. It occurs also as fen- 

 estrated membranes in arteries. These are formed by a coalescence of 



neighboring fibers. In the process of 

 occlusion of the postfetal ductus ar- 

 teriosus of the pig by increase in the 

 amount of the elastic tissue in the 

 wall of the artery, the new elastic 

 fibers arise both from latent fibro- 

 blasts and by delamination of fibers 

 from preformed elastic tissue (J. P. 

 Schaeffer, Jour. Exp. Med., vol. 19, 

 1914). 



Adipose Tissue (Fat Tissue). 

 Wherever areolar tissue occurs, adipose 

 tissue may also be found ; its distribu- 

 tion is therefore identical with that of 

 areolar tissue. It forms a consider- 

 able mass, panniculus adiposus, be- 

 neath the skin of many parts. In it 

 are embedded the kidneys, adrenals, 

 and many lymphatic nodes. The mes- 

 entery and omentum are freely sup- 

 plied with fat. The same tissue is 

 found in the grooves of the heart wall 

 and it also occupies the spaces of the mediastinum. 



Adipose tissue is composed of lobules or groups of fat cells which are 



t. c. 



ffy 



S/ 



FIG. 72. PORTION OF LIGAMENTUM 



NUCHJE OF Ox. 



conn. t. c., connective tissue cells. 

 (From Dahlgren and Kepner.) 



