THE FRONTIERS OF MEDICINE 



It has likewise been established that a nervous state 

 tends to raise the blood pressure, and it is known that 

 excessive amounts of tea and coffee may make the individual 

 more nervous than he would otherwise be. These practical 

 aspects of the subject are such that every man may make, 

 to some extent, his own diagnosis. 



From time to time it has been recognized that various 

 drugs will lower the blood pressure. This effect is brought 

 about by action on some of the factors concerned in main- 

 taining the blood pressure. Sometimes the decrease is 

 brief and therefore of but little use in the control of a long- 

 continued chronic condition. Other drugs have been used 

 in which the reduction of pressure took place over longer 

 periods of time. Then the question arises as to whether 

 or not the increased blood pressure may not be a mechanism 

 for maintaining the health rather than a serious factor 

 of disease. Upon such problems as these research workers 

 continue to spend their efforts in many hospitals. 



The Liver and Gall Bladder. The liver is the largest organ 

 in the human body. It weighs from three to four pounds. 

 It is well supplied with blood, and it is concerned with 

 many activities essential to life and to health. Under the 

 surface of the liver is the gall bladder, a pear-shaped sac 

 from three to four inches long. A tube comes from the 

 liver and joins a similar tube coming from the gall bladder 

 to make one common tube which empties into the intes- 

 tines. The liver is the great chemical center of the body. 

 When food is digested, it comes from the intestines to 

 the liver, and the products of digestion are changed — 

 built up or broken down — into other substances which are 

 needed by the various tissues. Glucose, for example, is 

 changed into a substance called glycogen, which is stored 

 in the liver; later, the glycogen is reconverted into 

 glucose and carried by the blood to the tissues as they 

 need it. 



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