78 



NORMAL HISTOLOGY. 



FIG. 64. 



-fb 



terwoven fibrous bundles renders the tissue easily distensible in all 

 directions and permits considerable freedom of motion between the 

 parts which it unites. 



In other situations the spaces in the tissue are smaller and the 



fibrous bundles closer together 

 and less tortuous in their arrange- 

 ment, so that the parts connected 

 with each other are more firmly 

 held in place. This form of the 

 tissue occurs in all the glandular 

 organs of the body, supporting 

 and holding in place the func- 

 tionally active tissues of the or- 

 gans and constituting the chief 

 constituents of their interstitia 

 (see Chapter VII.). To distin- 

 guish this form of fibrous tissue 

 from the areolar or more open 

 form it may be designated as 

 connective tissue in a more re- 

 stricted use of that term than 

 has hitherto been employed (Fig. 

 65, b, &') 



A still denser form of the tis- 

 sue occurs in the fasciae and apo- 

 neu roses, in which the fibres are 

 aggregated in thick bundles and 

 layers that run a comparatively 

 straight course and are firmly held 

 together. Ligaments and tendons differ from these only in the 

 greater density of the fibrous bundles and in their parallel arrange- 

 ment. These denser varieties of the tissues may be designated by 

 a restricted use of the term, fibrous tissue. 



4. Adipose Tissue (Fig. 65). Fat or adipose tissue is a modifica- 

 tion of the more open or loosely-textured areolar tissue, caused by 

 the accumulation within the cytoplasm of the cnboidal cells of drops 

 of oil or fat, The cells which have become the seat of this fatty 

 infiltration are enlarged, and their cytoplasm, with the enclosed 

 nucleus, is pressed to one side, the great bulk of the cell being occu- 

 pied by a single large globule of fat. This globule, together with 



Cell from subcutaneous tissue of human 

 embryo. (Spuler.) c, centrosome; fb, 

 fibrillse in the cytoplasm of the cell ; fb', 

 fibril detached from the cell, but evi- 

 dently derived from it. This cell corre- 

 sponds to c, c, and/, in Fig. 63. They are 

 sometimes called fibroblasts because of 

 their activity in the formation of fibres. 



