FAT. 



59 



The physical properties of this texture have been sufficiently indicated 

 in the foreo-oing description ; also its want of sensibility. The vital 

 contractility ascribed to certain portions of it is most probably due to 

 the presence of muscular tissue. 



Regeneration. — AYith the exception of the epithelium, no tissue 

 is so readily regenerated as the areolar. It is formed in the healing 

 of Tvounds and in the adhesion of inflamed surfaces. It is produced 

 also in many morbid growths. 



ADIPOSE TISSUE. 



The human body in the healthy state contains a considerable amount 

 of fatty matter of different kinds. Fat, as has been already stated, is 

 found m the blood and chyle, and in the lymph, but much more 

 sparingly. It exists, too, in several of the secretions, in some consti- 

 tuting'the chief ingredient ; and in one or other of its modifications it 

 enters into the composition of certain solid textures. But by far 

 the greater part of the fat of the body is inclosed in small cells or 

 vesicles, which, together with their contained matter, constitute the 

 adipose tissue. 



Distribution. — This tissue is not confined to any one region or 

 organ, but exists very generally throughout the body, accompanying 

 the still more widely distributed areolar 

 tissue in most though not in all parts in Fig- 33. 



which the latter is found. Still its dis- 

 tribution is not uniform, and there are 

 certain situations in which it is collected 

 more abundantly. It forms a consider- 

 able layer underneath the skin, and, 

 together with the subcutaneous areolar 

 tissue in which it is lodged, constitutes 

 in this situation what has been called 

 thepanmculKS aclijwsi/s. It is collected 

 in large quantity round certain internal 

 parts, especially the kidneys. It is seen 

 filling up the furrows on the surface 

 of the heart, and imbedding the vessels 

 of that organ underneath its serous 

 covering; and in various other situa- 

 tions it is deposited beneath the serous 

 membranes, or is collected between 

 their folds, as in the mesentery and 

 omentum, at first generally gathering 

 along the course of the blood-vessels and 

 at length accumulating very copiously. 

 Collections of fat are also common I'ouud 

 the joints, lying on the outer surftice of 

 the synovial membrane, and filling up 

 inequalities ; in many cases lodged, like 

 the fat of the omentum, in folds of the 

 membrane,which project into the articular 

 cavity. Lastly, the fat exists in large quantity in the marrow of bones. 

 On the other hand, there are some parts in which fat is never found 



Fig. 33. — Loose Areolar Tissue 

 WITH Fat-Cells ; of Man. (K61- 

 liker.) 



