I UK POSTERIOR VENA CAVA. 611) 



It begins in the sublmnbar region, at the great mcsenteiic artery, by the 

 union ot tlnvu largo roots; it is then directed forwards and a little to the 

 ri-Jtt. traversing the pancreatic ring, below the vena cava, and is at'ti-rwanls 

 li ilu'fd in tin- great posterior fissure of the liver, where it ramifies by forming 

 tin- siihhtjHitir f> ins, whose capillary divisions themselves give rise to the 

 ttelt. 



8*pfakepalie and sttbhepatic vents (Fig. 219, VP, VA). These vessels 

 having been already studied in tin: description of the liver, we need not 

 again occupy ourselves with them, but refer only to a peculiarity incompletely 

 noticed iii that description, with reference to the suprahepatic veins. 



We know that these vessels are divided into two categories, according to 

 the arrangement of their openings. The majority enter the vena cava in 

 forming a single confluent placed at the anterior extremity of the fissure in 

 the liver, at the diaphragmatic veins ; the others open separately over the 

 whole extent of the hepatic portion of the venous trunk. In carefully 

 examining the confluent towards which all the veins of the first group 

 converge, we recognise the embouchures of three principal veins, one coming 

 from each of the hepatic lobes, and furnished with three very thick, incom- 

 pli t.- valves. With regard to the vessels of the second group, M. Claude 

 Bernard * considers them to come, for the most part, directly from the sub- 

 hepatic veins, and not from the capillary network formed by the arborisation 

 of these veins in the lobules of the liver. It is true that injections readily 

 penetrate from the vena portse into the vena cava, but they do this quite as 

 much by passing along the large suprahepatic vessels as the canals of which 

 we now speak ; and, besides, if the material forced into the vena portae is 

 mixed with some imperfectly-powdered colouring matter, the injection will 

 arrive colourless, or but slightly tinged, in the suprahepatic vessels and the 

 vena cava. These facts, we see, do not militate in favour of M. Bernard's 



1 ' Leyons de Physiulogie Experimentale.' Paris, 1856. 



1, Anterior vena cava; 2, 2, Posterior vena cava; 3, Right pelvi-crural trunk, 

 divided at the ilio-sacral articulation ; 4, Left pelvi-crural trunk ; 5, Femoral 

 vein: t*>, Obturator vein; 7, Subsacral vein; 8, Left testicular vein; 9, Poste- 

 rior abdominal vein; 10, Kenal vein; 11, 11, Ascending branches of the a.-t.-nial 

 vein; 12, Vena azygos, with its intercostal branches, and in front the subdorsal 

 is branch, l.'i ; 14, <Ksophai;t-al vein; 1 .">, l>i>rsal, or dorso-imis<-ul:ir vein; 

 1'-. Cervical, or corvico-muscuhir vein; 17, Verti-ln-al vein: 18, Right axillary 

 . cut at the anterior border of the first rib; 19, Substcrnal, or internal 

 nummary vein; 20, Left axillary artery; 21, Termination of the left cephalic 

 vein; 22, Left jugular; 'j:i, Kight jugular: -4, Kxtnnal maxillary, or glosso- 

 "'oronary vein; 2*5, Angular vein of the eye; 27, SubzygomatU- 

 vein; 28, Posterior auricular vein; 29, Maxillo-imiM -ular vein; :;o. Internal 

 ii'i'il v.-in : .".I. Median subcutan- -vein; 



1'osterior radial vein: .">4, Basilic vein; 35, Plat, or cephalic vein; .:<',. 

 nary venous plexus; 37, Digital vein; 38, Internal metatarsi \. 

 Anti-rior root of the internal saphena Posterior root of ditto; 41, 



Internal saphena ; 42, Great coronary vein ; 4:>. Small mesaraic vein; 44. 1'i:'- 

 of the great mesaraic vein; 45, Trunk of the vmi porta- in it-; 

 siililtiinbar jwrtion, lodged in the pancreas; 46, The ame in tin- jo -ti-ri.ir li->ure 

 >t tin- livi-r: I., low it is seen entering the substance of the gland. si, Sul- 

 scapular hyoidetis muscle cut obliquely in the cliivi-tioii c.f the trn<'ln-.i ; r. < ' 

 jiaiiniciilus turneil down to e*|><.M- tin- jugular t-hamii-l ; o. lii-^ht aurirlt; of thi- 



: \. Posterior aorta ; O, Section of th>- ri-^ht hm^: K. I.-t't l<-l.e of ti; 

 iM'liiiiil tin- M-rti.n of the diaphragm; U, Hi-^ht k i up and fi>r\\.ud; 



i. <Ks..p|iagus: v, I'.ladder; s. Untiu. i ', Termination of 



that duct in tip i< uliiK-nt nf tin- jii<;iil 



