THE NERVES AND THEIR FUNCTIONS. 



158 



commands of the will ! Truly may it be said, " man is fear- 

 fully and wonderfully made." 



23.* The spinal nerves are classed according to the por- 

 tion of the spinal column from which they issue as the 

 neck, back, loins, and pelvis ; forming eight cervical, twelve 

 dorsal, five lumbar, and five sacral nerves ; all being con- 

 nected with the sympathetic. The four lower cervical and 

 first dorsal go to the arm-pit, where they form a complicated 

 plexus, from whence nerves issue to supply the arm and hand. 

 The dorsal nerves supply the integuments of the body, the 

 intercostal muscles, and those of the chest. The lumbar 

 and sacral nerves supply the muscles of the loins and abdo- 

 men, together with the lower limbs. 



24. FIFTH ORDER. Ganglionic Nerves. We have now 

 considered, somewhat minutely, that portion of the nervous 

 system which is called the cerebro-spinal, embracing the 

 brain, the material instrument of thought, the source and 

 channels of voluntary motion, and of instinctive movements 

 and sympathy. iThe ganglionic nerves jjare|sometimes called 

 great sympathetic, or the great intercostal ?. but sympathy 

 has been shown to be chiefly independent of it, except so 

 far as it receives filaments from the cerebro-spinal nerves ; 

 and it is called great, not so much from its size, as from its 

 supposed importance. 



A plexus of nerves. 



