CUTANEOUS AND INTERNAL SENSATIONS 1097 



ago, at least two elements are involved in the somewhat vague 

 sensation of hunger : the local sensation of emptiness in the stomach, 

 and the general sensations of malaise, depression, and weakness. 

 There is some evidence that the general sensations are in part at, 

 least dependent upon the state of the stomach. But it would 

 appear that at any rate, during prolonged deprivation of food a 

 general condition of the tissues may exist which can arouse in con- 

 sciousness the sensation of hunger, even after the stomach has been 

 amply filled. Thus a patient with a fistula in the upper part of 

 the small intestine constantly suffered from hunger in spite of the 

 enormous quantities of food consumed. The stomach always felt 

 full, but as most of the food escaped from the fistula, the tissues 

 continued to be starved, and the general sensation of hunger re- 

 mained (Hertz). In diabetes the same thing may be observed. 

 On the other hand, it was noted by Carlson and one of his pupils 

 that after a fast of five days practically all of the mental depression 

 and some of the feeling of weakness disappeared during the first 

 meal. He therefore concluded that the depression of the central 

 nervous system was essentially a reflex condition, depending prob- 

 ably on afferent impulses from the digestive tract, rather than a 

 result of deficiency of nutrient material in the blood. Complete 

 recovery from the bodily weakness, however, did not take place 

 till the second or third day after breaking the fast. 



Fig. 472. Commencement of Gastric Hunger Contractions (the Large Elevations 

 in a Man. At x she belt was tightened and the hunger contractions inhibited. 

 To be read from left to right (Carlson and Lewis). 



An important factor in the local sensations associated with 

 hunger is the strong periodical contractions of the empty stomach, 

 which have been shown to coincide with the hunger pains (Cannon 

 and Washburn). 



Carlson was able in observations on a man with a permanent 

 gastric fistula to confirm this coincidence Even when the empty 

 stomach was artificially caused to contract by distending it with a 



