LIVER. 



vbrx, l)ct\vecn the vena cava ant! afophagns ; thence it 

 afcends towards the front o'.i the iiifcrior furfaccof the liver, 

 and is immediately divided into two otiier fmalf eminence?. 

 One of thefe is I'lipcrior and poftcrior (l(;buhis caudatus), 

 connects the fmall lobe to the rell. of the liver, and palTos 

 obliquely towards the right, f.;parating the vena portarum 

 from the vena cava. It then becomes broader, and forms a 

 (liort fuperiicial groove, coatiKUOus wiih the riglit extremity 

 of the trunfverfo fiiTiire, and on which the vena portanmi 

 reds as it enters that lifl'i!re. Tlie other eminence is more 

 conliderable, and forms a kind of obtnfe papilla directed 

 forwards and downwards : this is the part properly calLd 

 lobiiliis Spigelii. Separated from the reft of the liver in 

 front by the tranfvcrfo lifiiire, behind by the vena cava, on 

 the left by tlie horizontal filTu-e, ar.d the canalis venofus 

 contained in it, on the ri^ht by the vena portarum before its 

 entrance into th • tranfverfe filT.re, tjiis eminence appears to 

 be coniie£led to the org^n only by the kind of root \:Ht 

 defcribed, and which palTes uiidcr the Tight lobes, between 

 the vena cava and vena portarum. But behind it is fartiitr 

 connedled by a fmall elonga ion, formed fometimes by the 

 fubftance of the liver, fometimes by a fold ot pcri'ont-um, 

 which ferves to complete a very fhcrt canal traverfed by the 

 vena cava. This lobulus Spigelii is placed between the two 

 orifices of the llomacli: it correfponds below to the panerca", 

 above to the right and left lobes ; in front of it is the li'.tle 

 om.entum. 



5. In the right lobe, in the front cf the right cx'remity 

 of the tranfverfe fiffure, and on the right of the lobulus 

 quadratus, appears the excavation that lodj^es the gall- 

 bladder. Tiiis is of an oval fignre, fuperfjcial, more or 

 lefs dil'ant from the longitudinal liflure, not covered by pe- 

 ritoneum, and lined only by the proper meirbrane of the 

 liver, and by cellular tiliue, which connetls it (Irongly to 

 the gall-bladder. 



6. Two Ihll more fuperiicial excavations are found q\iite 

 to the Tig'ht. Th" aiit'.rior correfponds to the hepatic 

 flexure of the colon, and the potteriwr to the right kidney 

 and renal -cap file. 



The aiTterior or thin edge of the liver is thin, ai^d inclined 

 downwards. In the natural fituation of the organ it corre- 

 fponds nearly to the level of the balls of tlve ehcft, being 

 fometimes a little above, but feldom. below it. Its direction 

 may be eafily conceived from the general defcription we 

 have given of the organ. It is turned ahnoft diredtiy down- 

 vards on the right, ar.d becomes more direftly anterior to- 

 wards the left. A notch is always feen in it towards the 

 left, and forms the commencement of the horizontal fiflure : 

 to the right of this there is a broader fuperiicial excavation 

 accommodated to ihe fundus of tho gall-bladder. 



The pollerior or thick margin is inclined upwards, not 

 fo long as the anterior, very thick on the right, and grows 

 gradually thraner towards the left. Its middle is clofely 

 connefted to the diaphragm by the coronary ligament ; and 

 the extremities are more loofely attached to the fim.e organ 

 by the lateral' ligaments. Two excavations may be oblerved 

 on this edge : a very deep and narrow one at the poflerior 

 edge of the horizontal liflure, between the great lobe and 

 the lobulus Spigelii, for the pafiiigc of the inferior vena 

 cava ; in this the orifices of the hepatic veins are feen. It 

 is very (lightly oblique from the left and below to the riglit 

 and upwards, and covers about three-fourths of the' cir- 

 cumference of the vein, fometimes indeed the whole of it, 

 forming a complete canal in the fubftance of the liver.' The 

 fecond hollow, much broader and more fuperiicial, formed in 

 the left lobe, correfponds to the vertebral column, the aorta, 

 a.id oefophagus. 



The right cxtre.-.iity of the liver is fitu.ited much lower 

 than the left, and is the moft bulky part of the organ. The 

 left is Very thin, extends more or kfs into the left hypo- 

 chondrium, reaching above tlie fpleen in iome lubjects. 



Organifili'jii of //'■■ liver. — This is very complicated ; bc- 

 fides its peculiar tiffue or parenchyma, the nature of whicii 

 is perhaps more oblcure than that of other glands, it re- 

 ceives a larger number of veffels. The greater part of the 

 blood, brought from the placenta to the fa-tus by the urn- 

 bilical vein, circulates throu.;h this organ; in the adult 

 we find only fome impervious traces of this vclfel. A pe- 

 culiar venous fyllem, that of the vena portarum, is at all 

 ages entirely diftributed in the liver. To thefe two orders 

 ©f vefTels, wh'ch are not found in other fituation?, we niuil 

 add the ramifications of the hepatic anery and veins, the 

 nerves, which are fmall for the organ, the lymphatic icdelf, 

 the excretory tubes, and the j/eculiar til'ue luciolcd by a 

 double membrane ; all of which mull be lep.ira'.ely con- 

 fidcred. 



Of the umbilical vfenous fyflem, which is fo remarkable 

 in the ioerus, nothing mote can he difucrned in the adult 

 than the fibrcus remains cf 'he umbilical vein and tannlis ve- 

 ni fus in the hori-zoiitul tffure of the hver. 



The general arrangement and the organifa'ion of the 

 vena portarum are defcribed in the article Heart, under the 

 head of Abdoir.hwl f\Jl(m of black blood. We h.'.ve to add here 

 only a few details belonging to their defcri; tion. 



1 . A numberof veins varying from three or four to feven or 

 eight, cf co!:fiderable fizc, come out of the fpleen, and run 

 torinouily in the fold ef peritoneum, which fixes that organ ti> 

 the ftcm.acli. After a Ihort courfe, in which they receive 

 branches from the latter, ihey unite near the pancieas into 

 a (ing'e trunk, called the fplcnic vein. 



2. The pancreas produces a confiderable number of fmall 

 irregular Vranches, joining indifferently cither of the prin- 

 cipal trunks of the vena portarum, but more particularly the 

 fplenic vein. 



3. Five orders cf venous branches come from the ftomach, 

 and end either in the trunk or in ih.e large branches, which 

 make up the vena portarum. i. Several go from the great 

 extremity to the conftitucnt branches, or to the trunk of the 

 fplcnic vein. 2. The pyloric vein, belonging to the fmall 

 curvature, opens into the trunk of the vena portarum. 

 J The fuperior gaftric or coronary ftomachic vein, follow, 

 ing the artery ot the fame name, joins the fplenic trur.k. 

 4, J. The right and left inferior gaftric veins run along the 

 great curvature, and join relpectively the trunk of the vena 

 portarum, and the Iplenic vein. 



ii-. The duodenal veii:s join either the right inferior gat- 

 trie, the fuperior melenteric, or vena pcrlarum. 



5. The veins of the fmall inteftine an.iilomofe, like the 

 arteries, and form a moll exterffive net-woik between the 

 two lamina? of the mefentery. The communications becom.e 

 fewer and the trunks larger, in proportion as they are m.ore 

 dillant from the inteftine : they form atlaft i^ or 20 veins, 

 which join fucceflively the large trunk of the fuperior 

 mefenteric vein accompanying the artery of the fame 

 nam.e. 



6. The veins of tlie ca:cum, right portion of the colon, 

 and right fide of the arch, loUow the courfe of the arteries, 

 and end, under the nan;es of ileo-caecal, right cohc, a.od 

 m.iddle colic, in the trunk of the fuperior mefenteric. 



7. The vcii.s, which return the blood from the left fide 

 of the arch of the colon, from the defcending colon, the 

 figmoid flexure andreflum, form as many principal branches 

 as there are chief divifions of the inferior mefenteric artery ; 

 a large trunk, accompanying that artery, is farmed by their 



% uaioa. 



