THE KIDNEYS 361 



to thrust the viscus forwards, while the other hand is placed 

 on the anterior abdominal wall, just below the costal margin. 

 The patient is instructed to take a deep breath, and, as the 

 abdominal wall collapses with expiration, the anterior hand is 

 pressed backwards and upwards under the costal margin in an 

 endeavour to catch the lower pole of the kidney between the 

 two hands. 



If the examination is carried out with the patient in the 

 dorsal decubitus, it may not be easy to determine whether 

 the kidney is movable or not. On this account the examina- 

 tion should be repeated with the patient sitting up, or, if 

 possible, in the erect attitude. 



NERVE-SUPPLY. The kidney receives its nerve-supply from 

 the renal plexus, which is an off-set from the aortic plexus of 

 sympathetic nerves (p. 188). These nerves have their centres 

 in the lower thoracic segments of the spinal medulla. 



As in the case of the liver (p. 264) and the lung (p. 356), 

 pathological processes may cause serious and even fatal lesions 

 of the kidney, without giving rise to any painful symptoms 

 referable to the viscus. 



Tumours of the Kidney, however, may give rise to referred 

 pain, not by a " viscero-sensory reflex" (p. 192), but by direct 

 pressure on the subcostal, ilio-hypogastric and ilio-inguinal 

 nerves (p. 360). Further, painful symptoms may be present in 

 cases of movable kidney owing to traction on the sympathetic 

 nerves or on the peritoneum. 



As a result of the absence of painful symptoms, for the 

 diagnosis of renal conditions the physician is almost entirely 

 dependent on the examination of the urine and the blood- 

 pressure, and, in some cases, he may receive additional in- 

 formation from radiograms. 



The Ureter. The ureter begins at the hilum of the kidney 

 and descends vertically through the abdomen at a distance of 

 about 1 1 inches from the median plane. When perfectly 

 normal, the ureter lies directly in front of the tips of the 

 transverse processes of the lumbar vertebrae, from which it is 



