THE KIDNEYS. 



175 



THE URINARY ORGANS. 

 THE KIDNEYS. 



Where are the Kidneys situated ? Posteriorly in the abdomen, one on 

 each side of the spinal column, behind the peritoneum, and extending from 

 the level of the nth rib to near the crest of the ileum. The right kidney is 

 lower than the left. 



State their Dimensions. Each one is about 4 inches by 2 by I, and 

 weighs from 4 to 6 oz. 



Enumerate their Relations. The 



Anterior Surface of the Right Kidney, is in relation with the right lobe of 

 the liver, descending duodenum, and the ascending colon. 



Anterior Surface of the Left Kidney, with the tail of the pancreas, descend- 

 ing colon, and part of the spleen. 



Posterior Surface, with the crus of the diaphragm, nth and I2th ribs, psoas 

 magnus, quadratus lumborum, and the aponeurosis of the transversalis muscle. 



Superior Extremity, is capped by the supra-renal capsule. 



Describe the Hilum of the Kidney. The Hilum is a fissure on the inner or 

 concave border, leading into the Sinus or cavity of the gland. It contains the 

 Renal Vein, in front. Renal Artery, next in order. 



Ureter, or Excretory Duct, behind and below. 



Describe the Kidney-structure. A vertical section presents the 

 Pelvis or Sinus, 6 the cavity, forming the beginning of the ureter 7 or ex' 



cretory duct of the gland. Its divisions are 



the 3 Infundibula 5 , and these are again 



divided into Calices 4 or pouches, into which 



open the orifices of the pyramids, 1000 orifices 



situated on each Papilla. 

 Medullary Substance,* consists chiefly of the 



tubes of Bellini and Henle, arranged in Pyra- 

 mids of Malpighi, whose apices project into 



the calices of the pelvis. 

 Cortical Substance," 1 forms the surface of the 



gland, and consists of uriniferous tubules 



(straight and convoluted), Malpighian bodies, 



blood-vessels, nerves, lymphatics, connective 



tissue, and a granular matrix. It is of a red 



color, and is prolonged down to the pelvis be- 

 tween the pyramids, these prolongations being 



named the Columns of Bertin. 



FIG. 



