MODE OF TERMINATION OF THE SENSORY NERVES 



467 



General Mode of Termination of the Sensory Nerves. The actual 

 termination of the sensory nerves on the general surface and in mucous 

 membranes is still a question of some obscurity. Although anatomists 

 have arrived at a pretty definite knowledge of the sensory corpuscles, it 

 must be remembered that there is an immense cutaneous and mucous 

 surface in which no corpuscles have as yet been demonstrated ; and it 

 is in these parts, endowed with what may be called general sensibility, 

 as distinguished from the sense of touch, that the mode of termination 

 of the nerves demands further study. 



According to Kolliker, in the great majority of instances the sensory 

 nerves terminate in some way in the hair-follicles ; and this would 

 account for the termination of the nerves in by far the greatest portion 

 of the skin, as there are few parts in which hair-follicles do not exist ; 



Fig. 106. Papilla of the skin of the palm of the hand (Sappey). 



I, papilla with two vascular loops ; 2, papilla with a tactile corpuscle ; 3, papilla with three vascular 

 loops ; 4, 5, large compound papillae ; 6, 6, vascular network beneath the papillae ; 7, 7, 7, 7, vascular 

 loops in the papillae; 8, 8, 8, 8, nerves beneath the papillae; 9, 9, 10, n, tactile corpuscles. 



but unfortunately the exact mode of connection of the nerves with these 

 follicles is not apparent. The following seems to be all that is posi- 

 tively known of the terminations of the nerves on the general surface : 



Medullated nerve-fibres form a plexus in the corium, which gives 

 off filaments, usually non-medullated, that terminate in the structures 

 just beneath the epidermis. That some fibres go to the hair-follicles, 

 there can be no doubt. It is thought by some histologists that pale 

 fibres form a network around and between the cells of the Malpighian 

 layer of the epidermis. A certain number of fibres pass to the non- 

 striated muscular fibres of the skin. A certain number pass to papillae 

 and terminate in tactile corpuscles, and others pass to papillae that have 

 no tactile corpuscles. 



In the mucous membranes the mode of termination is, in general 

 terms, by a delicate plexus just beneath the epithelium, coming from a 

 submucous plexus analogous to the deep cutaneous plexus. In certain 



