HISTOLOGY 



131 



The renal pelvis and ureter. — The funnel shaped pelvis surrounds the 

 renal papilla. In its wide part the epithelial lining consists of a single 

 layer of squamous cells which change gradually toward the narrow part first 

 to polyhedral, then to two or three layered, still farther to four or five 

 layered transitional type. At the wide part the lamina propria is very 

 delicate and becomes better developed at the narrow part. An inner circu- 



Glomerulus 



Renal vein 



— Renal artery 



Renal pelvis 



Capsule 



Fig. 61. — Kidney, region of pelvis and papilla. (X30.) 



lar smooth muscle layer appears first about at the level where the epithelium 

 becomes stratified, while still lower an outer longitudinal smooth muscle 

 layer is also distinguishable. Outside of this, loose connective tissue con- 

 taining many adipose cells surrounds the narrow end of the pelvis and the 

 ureter which arises here (Fig. 61). 



The ureter is a narrow tube which conducts the urine from the kidney 

 to the bladder. Its wall is composed of transitional epithelium, a fibrous 

 lamina propria, an inner circular and an outer longitudinal smooth muscle 

 coat and the adventitia consisting of loose connective tissue and many 



