THE TELA SUBCUTANEA 



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different parts of the body. In general those are best developed which have a direction parallel 

 with the usual lines of tension of the skin, hence it results that wounds of the skin tend to gape 

 most at right angles to these lines. The bundles take a direction nearly at right angles to the 

 long axis of the hmbs, and on the trunk run obliquely, caudally, and laterally from the spine 

 (figs. 1047, 1048). On the scalp, forehead, chin, and epigastrium, equally strong bundles cross 

 in all directions, and around wound, instead of being linear as elsewhere, appears as a ragged or 

 triangular hole. The arrangement of the connective-tissue bundles influences the arrangement 

 of the blood-vessels of the skin. 



The tela subcutanea or superficial fascia is also a fibrous vascular layer which 

 passes as a gradual transition without definite line of demarcation from the deep 

 surface of the tunica propria of the corium to connect it with the underlying 

 structures. 



Like the tunica propria it is composed of bundles of connective tissue containing elastic 

 fibres and fat, but the bundles are larger and more loosely arranged, and form more distinct 

 connective-tissue septa, which divide the fat, when present, into smaller and larger lobules. 

 Where these connecting strands are especially large and well defined, they are known as re- 

 tinacula. Over almost the whole surface of the body the connective-tissue strands of the tela 



Pigs. 1047 and 1048. — Diagrams Showing the Arrangement of the Connective 

 Tissue Bundles of the Skin on the Anterior and Posterior Surfaces of the Body. 

 (After Langer.) 



ms" 



are arranged nearly parallel with the surface, and bind the skin so loosely to the parts beneath 

 that it may stretch and move freely over the deeper parts. In some situations the connective- 

 tissue bundles of the tela subcutanea run almost at right angles to the surface and bind the skin 

 firmly to the deep fascia, as in the flexor surface of the hands and feet and in the scalp and face. 



The quantity of subcutaneous fat varies considerably in different parts of the 

 body. It is, for instance, entirely absent in the penis, scrotum, and eyehds. When 

 it is abundant, the subcutaneous layer is known as the panniculus adiposus. 



In some situations, as in the caudal portion of the abdomen and in the perineum, the 

 connective tissue is so arranged that the panniculus may be divided into layers, so that a 

 superficial and a deep layer of the superficial fascia may be recognised. The fat is well de- 

 veloped over the nates, volar surface of the hands and plantar surface of the feet, where it 

 serves as pads or cushions; in the scalp it appears as a single uniform lobulated layer between the 

 corium and the aponeurosis of the epicranial muscle; and on other parts of the surface it is some- 

 what unequally distributed and shows a tendency to accumulate in apparent disproportion in 

 some localities, as on the abdomen, over the symphysis pubis, about the mammae in females, 

 etc. Everywhere except on the scalp it may undergo rapid and visible increase or decrease 

 under the influence of change of nutrition. 



