THI-: vi :/.v>. 



opinion ; and there is every reason to believe that the system of the vena ) 

 ami that of tho vona cava do not communicate, in the adult, otherwise than 



by the capillary network which is 

 intermediate to the suMn'p.itir and 

 raprahepeiio vessels. If any other 

 nic-iiiis of communication exist, they 

 must bo extremely small. 



Constituent vessels of tin // n<i y/"/7</-. 

 The throe roots of this vein are tho 

 great and small mesenteries and tin; 

 splenic vein. 



The collateral affluents it re- 

 ceives on its course are principally 

 two : tho right gattro-epiplote veins and 

 anterior gastric. 



We will make a rapid survey of 

 all these vessels. 



1. Boots of the Vena Portce. 



A. GREAT MESENTERIO OB AN- 

 TERIOR MESARAIO VEIN (Fig. 293, 

 44; 294, 2, 7). This is an enormous 

 venous canal into which flows the 

 blood that has passed through tho 

 walls of tho email intestine, caecum, 

 large colon, and the origin of the small 

 colon, and whose divisions correspond 

 exactly to the different branches fur- 

 nished by the great mesenteric 

 artery. 



When traced from its opening to 

 its origin, in an inverse direction to 

 tho course of the blood, it is observed 

 to lie between the two colic arteries, 

 and proceed beyond the fold formed 

 by tho suprasternal and diaphragmatic 

 curvatures, beyond which it divides 

 into two satellite branches for tho 

 colic arteries, which anastomose in 

 arcade towards the pelvic curvature, 

 like the arteries they accompany. 



It is therefore by tho union of two 

 colic veins (Fig. 294, 8, 9) that the 

 great mesaraic vein is constituted, and 

 in -whose formation numerous collateral 

 affluents concur ; among these may bo 

 noticed tho two ccccal veins (Fig. 294, 

 5, G), tho ilio-caxal vein (Fig. 294, 4) 

 coming from the origin of the floating 

 colon, and the veins of the small intes- 

 tine : vessels arranged so exactly like 

 tho corresponding arteries that wo maj 

 of thorn. 



THE VENA PORT.E AND ITS ROOTS ; PARTLY 

 THEORETICAL. 



1, Trunk of the vena porta: ; 2, Its origin ; 

 3, Veins of the small intestine; 4, llio- 

 csecal vein ; 5, External caecal vein ; 6, In- 

 ternal cwcal vein ; 7, Great mesaraic vein ; 

 8, 9, Colic veins forming the roots of that 

 vessel ; 10, Collateral vein sometimes con- 

 tinuing the left colic, and joining the great 

 mesaraic vein near its origin ; 1 1, Com- 

 mon confluent of the small mcsaniir :ui 1 

 splenic veins; 12, Small mesaraic vein ami 

 its collateral branches ; 13, Splenic vein ; 

 14, Left gastro-epiploic vein; 15, Right 

 ditto ; 16, Posterior gastric vein. a, 

 Stomach; 6, Duodenum; c, Small intes- 

 tine ; d, Caecum ; e, Large colon ; /, Float- 

 ing colon ; <;, Rectum ; /), Portion of the 

 grant omentum ; i, Spleen ; j, Mesentery ; 

 k, Colic mesentery. 



dispense with any further description 



