50 



HANDBOOK OF PHYSIOLOGY. 



film, closely pressed against the cell-wall, and with a nucleus imbedded 

 in its substance (figs. 48 and 49). 



Under certain circumstances this process may be reversed and fat- 

 cells may be changed back into connective-tissue corpuscles. 



Vessels and Nerves. 

 A large number of blood- 

 vessels are found in adipose 

 tissue, which subdivide un- 

 til each lobule of fat con- 

 tains a fine meshwork of 

 capillaries ensheathiug each 

 individual fat-globule (fig. 

 50). Although nerve fibres 

 pass through the tissue, no 

 nerves have been demon- 

 strated to terminate in it. 



The Uses of Adipose 

 Tissue. Among the uses 

 of adipose tissue these are 

 the chief: 



a. It serves as a store of 

 combustible matter which 

 may be reabsorbed into the 

 blood when occasion requires, and, being used up in the metabolism of 

 the tissues, may help to preserve the heat of the body. 



Fig. 50. Blood-vessels of adipose tissue. A. Minute flat- 

 tened fat-lobule, in which the vessels only are represented. 

 a, The terminal artery ; r, the primitive vein ; b, the fat- 

 vesicles of one border of the lobule separately represented. 

 X 100. B. Plan of the arrangement of the capillaries (c) on 

 the exterior of the vesicles ; more highly magnified. (Todd 

 and Bowman.) 



W 



Fig. 51. 



Fig. 52. 



Fig. 51. A lobule of developing adipose tissue from an eight months' foetus, a, Spherical or, 

 from pressure, polyhedral cells with large central nucleus, surrounded by a finely reticulated sub- 



Drawn by Treves. 



Fig. 52. Branched connective-tissue corpuscles, developing into fat-cells. (Klein.) 



