50 



THE INDIVIDUAL ORGANISM 



of the dermis may contain many globular fat cells and is one of the prin- 

 cipal regions for the storage of body fat. 



As a receptor system, the dermis contains thousands of nerve endings 

 for the reception of heat, cold, touch, pressure, and pain stimuli. Indi- 



lymph 

 vesse 



dermis 



nerves 



sweat 

 gland 



malpighian 

 layer 



capillary 

 network 



sebaceous 

 gland 



hair 



erector 



muscles 



hair 



connective 

 tissue 

 and fat 



d vessel 



Fig. 3.13. A stereogram of the structure of the skin. 



vidual receptors for each of these sensations occur over all of the body 

 surface, although they are much more closely spaced in some regions 

 than in others. Touch receptors, for instance, are many times more 

 numerous per unit of surface on the finger tips than on the back of the 

 hand and much more numerous on the back of the hand than on the 

 small of the back. 



