224 



LABORATORY MANUAL FOR VERTEBRATE ANATOMY 



located the kidney, identify the renal portal vein near the lateral margin of its 

 dorsal surface. At the place where the renal portal vein passes from the body 

 wall to the surface of the kidney, the vein receives the caudal vein, which ascends 

 from the tail, forks, and passes to the surface of the posterior end of each kidney. 



D 



FIG. 57. Diagrams to show the origin of the postcaval vein and the changes in the abdominal 

 vein in amphibians and reptiles. A, elasmobranch stage, same as in Figure 55^; the lateral abdominal 

 veins i enter the common cardinal veins c and are not connected with the renal portal veins p. B, the 

 lateral abdominals i have joined the renal portals at / posteriorly, and anteriorly pass into the liver /, 

 where they unite with the hepatic portal vein //; a new vein, the postcaval vein g, is seen growing caudad 

 from the liver/ where it arises from the hepatic veins o. C, condition in the adults of urodele amphibi- 

 ans; the postcaval vein g has reached and fused with the posterior cardinals e and the subcardinals j 

 at the point r; the two lateral abdominal veins have united to form the ventral abdominal vein i which 

 empties into the hepatic portal h. D, condition in adult reptiles; the anterior portions of the posterior 

 cardinal veins n are obliterated, leaving the postcaval vein g as the sole drainage for the subcardinals j 

 and the kidneys k; the two lateral abdominal veins remain separate as in elasmobranchs. a, anterior 

 cardinal vein; b, sinus venosus; c, common cardinal vein; d, subclavian vein; e, posterior cardinal 

 vein; /, liver; g, postcaval vein; h, hepatic portal vein; i, lateral (or in C ventral) abdominal vein; 

 j, subcardinal vein; k, kidney; /, iliac or femoral vein; m, caudal vein; , obliterated part of the pos- 

 terior cardinals; o, hepatic veins; p, renal portal veins; q, pelvic veins; r, union of postcaval, posterior 

 cardinals, and subcardinals; s, union of postcaval and subcardinals; I, union of abdominal vein with 

 renal portal system. 



The renal portal vein runs forward along the surface of the kidney, into the sub- 

 stance of which it sends numerous branches. It also receives branches from the 

 body wall. 



Draw the renal portal system. 



It will be seen that the ventral abdominal vein forms a connection between 

 the renal portal and hepatic portal systems. Blood from the hind legs and tail 



