82 



NORMAL HISTOLOGY. 



spaces separating them. The name is derived from that form in 

 which the structure is open and the courses of the fibrous bundles 

 very diverse, so that thev interlace, leaving relatively large spaces 

 betweeu them. In this form it occurs in the subcutaneous tissues, 

 between the muscles, forming the loose fascia? in that situation, and 

 in many other parts of the body where adjacent structures are 

 loosely connected with each other. The sinuous course of the in- 

 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 



Fig. 66. 



- 



\ \ M 



fb' V- 





-/» 



\ 



■ 

 ■ 



tissue occurs in all the glandular 

 organs of the body, supporting 

 and holding in place the func- 

 tional] v 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 con- 

 nective tissue in a more restricted 

 use of that term than has hitherto 

 been employed or as interstitial 

 connective tissue (Fig. 67, b, b'). 



A still denser form of the tis- 

 sue occurs in the fascia? and apo- 

 neuroses, 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. 



• 





Cell from subcutaneous tissue of human 

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

 fibrilke in the cytoplasm of the cell : fV, 

 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. 



