URINARY ORGANS OF THE PIG 557 



the dorsal border of the Hver. The left adrenal lies on the medial face of the 

 posterior vena cava, just behind the anterior mesenteric artery, and is therefore 

 practically median in position. It is flattened, and irregularly triangular or heart- 

 shaped in outline. Its left face is related to the dorsal sac of the rumen. Its right 

 face is related to the vena cava, and presents a large emergent vein. The posterior 

 border or base is deeply notched. The left adrenal does not migrate with the kid- 

 ney, but retains its primitive position; it lies usually two or three inches (ca. 5-8 

 cm.) in front of a transverse plane through the anterior pole of the left kidney. 



The adrenals of the sheep are both bean-shaped. The right one lies along 

 the anterior part of the medial border of the kidney, at the angle of the junction of 

 the right renal vein and the posterior vena cava. It is a little over an inch (ca. 



Posterior pole 



Groove for vena cava 



Atikrior pole 



Anterior pole 



Fig. 509. — Left Adrenal of Ox; Ventral ■\^iew. Fig. 510. — Right Adrenal of Ox; Ventral View. 



Hardened in situ. Hardened in situ. 



3 cm.) long, and about half as wide. The left adrenal is usually longer, and is 

 flatter and somewhat bent. It lies across the left renal vein, to which it is at- 

 tached; it is not in contact with the kidney, from which it may be separated by a 

 distance of nearly two inches (ca. 4 cm.). 



URINARY ORGANS OF THE PIG 



The kidneys are smooth and bean-shaped; they are more flattened dorso- 

 ventrally, more elongated, and smaller at the extremities than those of the dog. 

 The length is about twice the width. They are usually almost symmetrically placed 

 ventral to the transverse processes of the first four lumbar vertebra, but the left 

 kidney is often a little further forward than the right one. The lateral border lies 

 against the flank parallel with the edge of the longissimus muscle. The posterior 

 extremity is usually about midway between the last rib and the tuber coxae. The 

 anterior extremity of the right kidney has no contact with the liver. 



Variations in position are not rare, and involve the left kidney of tener than the right ; the 

 former has been found near the pelvic inlet. When a fifteenth rib is present the anterior end of 

 the kidney is usually ventral to it. The right kidney is usually separated from the liver by an 

 interval of an inch or more. Absence of the left kidney has been recorded. 



