CHAPTER XXVI 

 ORGAN SENSATIONS 



THE organ sensations are produced by the stimulations of 

 sensory nerves of an organ by the internal processes taking 

 place in that organ. 



They may be classified as follows : 



1 . Sensations of pain may proceed from all organs of the 

 body. The quality of these sensations is the same as that 

 of the pain sensations from the skin. But the power of 

 localizing the pain in the organ is very imperfect. 



2. The sensation of muscle tension. This enables us to 

 estimate the weight of a raised body. The muscular sense 

 is measured by determining the accuracy with which the 

 weight of a raised body is estimated. 



These sensations are produced by the stimulation of the 

 sensory nerves not only in the muscles, but also in the 

 tendons. In fact the nerves of the tendons seem to be of 

 gneater importance for the sensations of tension than those 

 of the muscles. But the nerves of the muscles sooner call 

 forth sensations of the degree of muscular activity (fatigue 

 sensation). 



3. The position of the limbs of the body is probably per- 

 ceived by the sensibility of the joints, which may be regarded 

 as closely related to the tactile sensation of the skin. 



The sensibility of muscles, tendons, and joints serves in 

 judging the position and movements of the body. 



Centripetal fibres from the muscles, tendons, and joints 

 also call forth reflexly coordinated movements for the main- 

 tenance of the equilibrium of the body. If the centripetal 



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