350 



THE VERTEBRATE BODY 



ventral side of the cloaca into which the urine may back up until ready 

 to be eliminated. 



In human excretion all the blood which reaches the kidney is carried 

 by the renal artery and returned to the venous system by the renal vein 



Fat bodies 



Testes 

 Vasa efferentia 



Urogenital 

 duct 



Vestigial 

 oviduct 



Seminal vesicle 

 Urinary bladder 

 Anus 



MALE 



FEMALE 



Ostium 



Ovary 

 (containing eggs) 



Oviduct 



Kidney 



Ureter 



Uterus 



Cloaca 



Fig. 24.1. Urogenital systems of the frog. The organs of the male are shown on the 



left and those of the female on the right. The urinary bladder is present in both sexes 



although it is tilted over on the male side in this diagram. 



—there is no renal portal vein in man. The human kidney is more com- 

 pact than that of the frog. It consists of an outer cortex, an inner 

 medulla, and a cavity which is known as the pelvis. The kidney tubules 

 are arranged in groups called pyramids and each pyramid has a projec- 

 tion, the papilla, extending into the pelvis. The indented side of the 

 kidney, the hilum, is the region where the blood vessels enter as well as 



