400 



ANATOMY FOR NURSES 



[Chap. XIX 



action, which is the chief inethod of response, is the most im- 

 portant vital phenomenon peculiar to animals possessing any 

 nervous svstem whatsoever. 



Fig. 190. — Diagram of Nervous System, a, a, cortex of cerebral hemi- 

 spheres ; h, b, cell-body and dendrites of upper motor neurone, situated in cerebral 

 cortex ; h', axis cylinder of ujjper motor neuroiic, branching at its termination near 

 the dendrites of lower motor neurone, situated in the ventral horn of gray matter 

 in the spinal cord ; B, axis cylinder of lower motor neurone passing to its termina- 

 tion in a voluntary muscle fibre B" ; C, cell-body and dendrites of upper sensory 

 neurone, situated in the medulla oblongata ; C, C, axis cylinders of upper sensory 

 neurone, terminating in cortex ; c, cell-body of lower sensory neurone, situated in 

 the dorsal root ganglion ; c'", dendrite of lower motor neurone, conducting impulses 

 from the periphery to the central nervous system ; c", long branch of lower sen- 

 sory neurone, conducting impulses toward the brain ; c', short branch of lower 

 sensory neurone, conducting impulses direct to ventral horn. (For the sake of 

 simplicity the connections with the cerebellum are omitted.) 



