504 



PRINCIPLES OF GENERAL PHYSIOLOGY 



the object. As we shall see in more detail in the following chapter, the analys a 

 consists of something more complex than the peripheral receptors alone, ole 

 includes these, but is continued to their central connections in the brain, ai of 

 these latter are often very complex, reaching to the highest centres. As ;els 



Touch, direct path 

 Special direction 

 Position 



ey 



J -Touch, crossed path 



l- Pain 



T -Cold 



,..Heat 



FIG. 158. DIAGRAM OF FIRST STAGES OF CENTRAL ANALYSIS AND INTEGRATION OF 

 SENSORY IMPULSES FROM THE SKIN. 



The outer (lotted lines mark the lateral Ixmndaries of the spinal cord. The centre line is the middle of the cord. 

 The letters, T, P, C, U, refer to synapses with cells concerned with touch, pain, cold, and heat respect h civ. 

 The lines represent bundles of nerve filirt-s. 



(Head.) 



example, Fig. 158, which is a diagram given by Head of the partial analysis and 

 reintegration, in the lower centres of the spinal cord and the bulb, of the three 

 different sets of receptors in the skin and the underlying structures of the hand, 

 maybe glanced at. The meaning of the names "protopathic," "epicritic," and 

 "deep" sensibility will be explained later (page 514). For the present, we may 



