EXCRETION. 



What is the normal direction of the ureter movements ? Can the 

 movements be induced in response to a mechanical or electrical 

 stimulus ? Are the movements rhythmical or irregular ? 



2. Urine Flow. Kidney Volume. Introduce a fine glass can- 

 nula into the ureter, near the bladder or through the ureteral 

 opening into the bladder. The 

 speed of urine flow may be re- 

 corded by allowing the drops 

 from the end of the cannula to 

 fall upon a lever, made for the 

 purpose and connected with a 

 tambour membrane. This tam- 

 bour is connected, through rubber 

 tubing, with a second tambour 

 whose lever is arranged to write 

 upon the smoked paper of a 

 slowly revolving drum. 



The changes in volume of the 

 kidney may be determined by 



means of a plethysmograph arrangement known as an oncometer. 

 The oncometer, as generally used, consists of a metal jacket lined 

 with some membrane for enclosing the kidney. There is an open- 

 ing for the passage in and out of the kidney vessels artery, vein, 

 and ureter. The space between the membrane and the jacket is 

 filled with oil. This space is connected through tubing with a 

 piston recorder whose lever is arranged to write upon the smoked 

 paper of a revolving drum. In this way a curve of kidney volume 

 is written. A simple form of air oncometer is shown in Fig. 39. 



The kidney is partly encased in a rubber balloon inflated with 

 air. The changes in pressure in the balloon are transmitted, 

 through rubber tubing, to a recording tambour or bellows re- 

 corder. 



The bellows recorder devised by Brodie is far preferable to the 

 tambour as a recorder of volume changes. It can be easily made 

 hi the laboratory and consists of two rectangles, hinged with thin 



FIG. 39. Oncometer, Simple Form. 

 B, Metal jacket ; O, opening for kid- 

 ney vessels; C, rubber balloon, in- 

 flated with air, partly surrounding 

 the kidney and connected through T 

 with a recording tambour. 



