viii THE EXCRETION OF UEINE 459 



maximum quantity of urine flowing into the bladder at a single 

 peristaltic contraction does not exceed 4 c.c. (Zamshin, 1887). 



It may be assumed by analogy with what takes place in the 

 heart and blood-vessels that the automatic, fundamentally 

 muscular rhythm of the ureters is regulated by the activity of the 

 intrinsic ganglia and the extrinsic ganglia, both in the sympathetic 

 system and in the cerebrospinal system. The experiments of 

 Protopopow (1897) in fact show that section of the great splanchnic 

 produces a delay in the peristaltic rhythm of the ureter of the 

 same side, while excitation of its peripheral end always produces 

 acceleration. 



According to Protopopow's numerous experiments, the effect 

 of the various operations by which the circulation in the kidneys 

 and ureters is modified are variously expressed in the movements 

 of the ureters. To cite his principal results : 



(a) In acute asphyxia the contractions of the ureters become 

 more marked and frequent, as in all other plain muscular organs. 

 (&) When the secretion of urine ceases owing to ligation of the 

 renal artery, the contraction of the ureters becomes slower at 

 first, but subsequently returns to the same frequency as before, 

 (c) After occlusion of the aorta above the point at which the 

 renal artery is given off, there is in consequence of the anaemia a 

 marked slowing of the contractions of the ureters, which return to 

 the normal rhythm as soon as the aorta is reopened, (d) After 

 occlusion of the inferior vena cava above the mouth of the vas 

 efferens there is a marked and persistent acceleration in the 

 rhythmical movements of the ureters, due to the passive hyperaemia. 

 (e) With increased frequency of the drops of fluid which trickle 

 into the ureter its contractions are accelerated, more or less, 

 according to the nature of the fluid. (/) Ligation of the upper 

 part of the ureter immediately above the pelvis produces a 

 marked slowing, followed by complete arrest, of its movements. 

 (#) Atropine at first produces acceleration, afterwards retardation, 

 and finally arrest of the contractions of the ureter. (7i) Some 

 diuretics, i.e. diuretine and adonidine, do not modify the frequency 

 of the movements of the ureters; caffeine, on the contrary, 

 accelerates them in small doses, delays them in large. 



The latest work on the movement of the ureters, carried out 

 by Lina Stern in Prevost's laboratory (1903), confirms the above 

 conclusions as a whole. Unlike Protopopow's results, however, 

 section of the splanchnic in the dog, produced acceleration, and 

 stimulation of its peripheral end, inhibition of the movements. 

 According to this author the splanchnic contains both accelerator 

 and inhibitory fibres; the action of the latter is favoured by 

 atropine. According to Fagge (1902), on the contrary, stimula- 

 tion of the hypogastrics accelerates the movements of the ureters, 

 while stimulation of the splanchnics produces no effect. 



