ABDOMINAL CAVITY 



533 



Calice 



large number of short stunted secondary divisions called calices 

 or infundibula, which are attached to the walls of the sinus. 



The kidney should now be cut into two in the longitudinal direction. 

 Use a large knife, and, entering it at the lateral border, carry it steadily 

 through the gland sub- 

 stance to the hilus. 



An examination 

 of the cut surface 

 of the kidney will 

 show that its sub- 

 stance is arranged 

 in two parts a 

 medullary and a 

 cortical. The 

 medullary portion is 

 seen to consist of 

 dark -coloured, 

 faintly striated 

 pyramidal masses, 

 the bases of which 

 are directed to- 

 wards the periphery, 

 whilst their apices 

 are free and project 

 into the sinus. On 

 the sinus wall each 

 of these appears in 

 the form of a pro- 

 minent mammillary 

 projection, called a 

 renal papilla, which 

 projects into one of 

 the calices of the 

 pelvis of the ureter 

 (Fig. 210). If the 



Pelvis 



Ureter 



G. 209. From a figure by Max Brb'del to show 

 the form of the Pelvis of the Ureter and the 

 Calices, as well as the relation of the rn^in 

 branches of the Renal Artery to these. The 

 ureter, pelvis, calices, and arteries were injected 

 with celloidin, and then the kidney substance 

 was removed by means of a digesting fluid. It 

 is thus a cast of the pelvis and calices which is 

 represented, and the cupped appearance of each 

 calyx shows the manner in which the corre- 

 sponding renal papilla projects into the calyx. 



kidney be squeezed, 

 fluid will be seen to exude from these papillae, showing 

 that the tubuli uriniferi open upon their surface. The 

 number of pyramids and renal papillae vary from eight 

 to twenty. Usually there are more than twelve. A single 

 calyx of the ureter may surround one, two, or even three 

 renal papillae, and receive the urine which issues from the 

 i 34 & 



