CHAPTER XXV 

 CUTANEOUS SENSATIONS 



The sense organs here dealt with are chiefly located in the outer 

 skin, but are also found in some parts of the mucous membranes 

 bordering on the skin, for example that of the jaws, mouth, nose, 

 conjunctiva, anus, vagina, and urethra. One kind of these sense 

 organs is present not only in the skin and mucous membrane, but 

 in all organs of the body the sense organs of pain. 



i. The organs of the tactile sensation. The cutaneous 

 sense organs are composed of the endings of sensory nerves 

 in the skin. These endings may be classified as follows: 



1. Free nerve endings between the epithelial cells. 



2. The ncrvc-wrcath of hairs which surround the hair- 

 bulb just beneath the opening of the sebaceous glands. 



3. Tactile cells are found in the deepest layers of the 

 epidermis and the neighboring layers of the cutis vera in 

 which are found non-medullated nerve fibres. 



4. End-bulbs. These are spherical or oval bodies com- 

 posed of a connective-tissue capsule and a granular jelly-like 

 medulla in which the nerve fibres end. In this class 

 belong: 



(a) The tactile corpuscles of Mcissner, elliptical, trans- 

 versely striated structures. The nerve endings in these 

 corpuscles form a complicated network. 



(b) The end-bulbs of Krauze, cylindrical structures in 

 which the axis cylinders are straight and end free. 



(c) The genital corpuscles, oval, unstriated bodies much 

 similar to the tactile corpuscles. 



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