510 



THE NERVOUS SYSTEM. 



given spot or area contractions of certain muscles or groups of 

 muscles follow, and when its extirpation causes paralysis of these 

 muscles, such spot or area is said to be the motor area for these 

 muscles. 



The following statement summarizes in a general way what 

 is known with reference to cerebral localization in the human 

 subject : 



Motor Areas (Figs. 300, 301). It has been noted that the 



FIG. 300. The motor areas on the outer surface of the brain. 



FIG. 301. The motor areas on the median surface of the brain. 



Rolandic area is also called sensorimotor and kinesthetic. This is 

 because it has been determined that the sensory fibers from the 

 skin and also from muscles terminate in the Rolandic area, as well 

 as that the motor fibers have their origin here. 



The motor areas are grouped about the fissure of Rolando and 

 are as follows : 



