THE URINARY SYSTEM 



325 



the kidney projects into the pelvis, or upper expanded beginning of 

 the ureter (Figs. 221, a and 222, g) in the form of papilla; (Figs. 221, h 

 and 222, 0). The number of papilLne varies from ten to fifteen, 



Fig. 222. 



Fig. 223. 



Fig. 222. — Longitudinal Section of Kidney Through Hilum. a, Cortical pyramid; 

 h, medullary ray; c, medulla; d, cortex; e, renal calyx;/, hilum; g, ureter; h, renal artery; 

 i, obliquely cut tubules of medulla; j and k, renal arches; I, coluinn of Bertini; m, 

 connective tissue and fat surrounding renal vessels; n, medulla cut obhqWy; 0, papilla; 

 p, medullary pyramid. (Merkel-Henle.) » 



Fig. 223.— Scheme of Uriniferous Tubule and of the Blood-vessels of the Kidney 

 showing their relation to each other and to the different parts of the kidney. G, Glorner- 

 ulus; BC, Bowman's capsule; N, neck; PC, proximal convoluted tubule; S, spiral 

 tubule; D, descending arm of Henle's loop; L, Henle's loop; A, ascending arm of Henle's 

 loop; I, DC, distal convoluted tubule; AC, arched tubule; SC, straight collecting tubule; 

 ED, duct of BeUini; ^, arcuate artery, and V, arcuate vein, giving oS interlobular vessels 

 to cortex and vasa recta to medulla; a, afferent vessel of glomerulus; c, efferent vessel of 

 glomerulus; c, capillary network in cortical labyrinth; s, stellate veins; vr, vasa recta and 

 capillary network of medulla. (Pearsol.) 



corresponding to the number of lobes in the foetal kidney. The 

 pyramidal segment of medulla, the apex of which is a papilla — in 

 other words, the medullary portion of a foetal lobe — is known as a 



