PHYSIOLOGY OF MAN. 



CHAPTER I. 



PHYSIOLOGICAL DIVISIONS AND STRUCTURE OF THE NERVOUS 



SYSTEM. 



General considerations Divisions of the nervous system Physiological anatomy 

 of the nervous tissue Anatomical divisions of the nervous tissue Medul- 

 lated nerve-fibres Simple, or non-medullated nerve-fibres Gelatinous 

 nerve-fibres (fibres of Remak) Accessory anatomical elements of the 

 nerves Branching and course of the nerves Termination of the nerves 

 in the muscular tissue Termination of the nerves in glands Terminations 

 of the sensory nerves-r- Corpuscles of Pacini, or of Yater Tactile corpus- 

 cles Terminal bulbs Structure of the nerve-centres Nerve-cells Con- 

 nection of the cells with the fibres and with each other Accessory anatom- 

 ical elements of the nerve-centres Composition of the nervous substance 

 Regeneration of the nervous tissue Reunion of nerve-fibres. 



THE nervous system is anatomically distinct in all ani- 

 mals, except those lowest in the scale of being. It is useless 

 to speculate upon the question of the existence of matter en- 

 dowed with properties analogous to those observed in the 

 nervous system of the higher animals, in beings so low in 

 their organization as to present no, divisions into anatomical 

 elements ; for the present condition of physiological science 

 does not admit of the recognition of functions without organs. 

 All animals that present any thing like nervous functions pre- 

 sent also an anatomically distinct nervous system. "Within 

 certain limits, the perfection of the animal organization de- 

 pends upon the general development of the nervous system. 



High in the animal scale, as in the warm-blooded ani- 



