THE PORTAL SYSTEM. 



925 



Practical Considerations. — The portal system may be obstructed by (a) 

 tumors or swellings involving the liver itself, as carcinoma, hydatids, or abscess ; (S) 

 enlargement of the gall-bladder from new growth or from concretions ; (r) tumors 

 of contiguous structures, as disease of lymph-nodes in the portal fissure or between 

 the layers of the lesser omentum, or carcinoma of the head^of the pancreas ; {d) 

 disease of the liver tissue, especially cirrhosis (chronic interstitial hepatitis) in 

 which the interlobular veins are compressed by the contraction of the connective 



Fig. 775. 



External jugular vein 



Cephalic veia 

 Axillary vein 



External jugular vein 



Cephalic vein 



Axillary artery 

 Axillary veia 



Brachial 

 ^ veins 



Subscapular vein 



III., I\'..and V 

 anterior perforating 

 veins and tributary of 

 musculo- phrenic vein- 



Tributaries of 

 superior epigastric vein 



Tributary of 



deep epigastric vein 



Thoraco-epigastric vein 



Superficial 



circumflex iliac vein 



Saphenous opening 



Femoral vein 



Internal saphenous vein 



v., VI., and VII. 



intercostal vein 



Tributary of 



musculo-phrenic vein 



Thoraco-epigastric vein 



Tributary of 



deep epigastric vein 



Superficial epigastric vera 



Femoral vein 



Deep dorsal vein of penis 



■Superficial 



dorsal vein of penis 



ilnternal saphenous vein 



Superficial veins of anterior body-wall ; pectoralis and external intercostal muscles (of 

 fifth to seventh intercostal spaces) on left side have been removed. 



tissue in the spaces between the lobules ; (.f) valvular disease of the heart leading to 

 backward pressure through the cava and hepatic and intralobular veins which finally 

 reaches the terminal capillaries of the portal vein and then the interlobular veins 

 and the entire portal system, resulting in some cases in the so-called nutmeg liver 

 (cyanotic atrophy). The consequences of portal obstruction are various, but may, as 

 a rule, easily be understood by referring each symptom to its anatomical basis in 



