URETER PRESSURE. 



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metric effect. The renal tubules and vessels lie pressed together within 

 a capsule which is but slightly elastic, hence such a sudden rise in blood- 

 pressure as in Fig. 1, due to the injection of a 20/o solution of sodium 

 sulphate, caused at once a rise in ureter-pressure. And as further, 

 there may occur, as pointed out by Loewi, a dilatation of the vessels 

 of the kidneys, which may be entirely out of proportion to the dilatation 



Fig. 1. Fig. 2. 



Fig. 1. Dog. Exp. V. May 12th. Upper line, blood-pressure; 2nd, ureter; 3rd, 

 outflow other ureter ; 4th, clock, 10 second intervals. 



Fig. 2. Exp. XXVII. Dog. As in Fig. 4, except that the signal is the ureter base line. 

 Decapsulated kidney. Stimulation of vagus. Plethysmograph is set to left of blood and 

 ureter manometers. 



of the entire kidney, this alone may cause a sudden rise owing to the 

 forcing of urine out of the tubules due to their compression by the 

 vessels. The ureter-pressure therefore depends very largely upon the 

 local blood-pressure in the kidney. The extent to which this is true 

 may be seen in Figs. 2, 3 and 4. It may be noted that these curves 

 show that a rise in general blood-pressure may be accompanied by a 

 fall in ureter-pressure due to constriction of the kidney vessels (splanchnic 



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