LIVER. 



Iiepatic arter\'. Its fize is about that of a large writing 

 quill, its figure cylindrical, and its length from four to fix 

 inches. At about an inch or an inch and a half from tlie 

 liver, we obferve in it the fimple round opening of the cyftic 

 fludl. From this part to its termination it generally goes 

 by the name of ductus communis choledochus ; but the 

 dilbnction is quite an artificial one. • When it arrives tit-ar the 

 duodenum, it becomes covered by the pancreas, which ad- 

 heres clofcly to it, and advances along the poiterior and in- 

 ferior portion of the fecomi flexure of the duodenum. It 

 penetrates the niufcular coat and that intcilinc, and receives 

 tiie termination of the pancreatic dutl. Having pafTed ob- 

 liquely between the raufcnlar and mucous coats, for tlie 

 fpace of an inch nearly, it penetrates the latter, and opens 

 into the inteftine by a Imall orifice on OTie of its folds. 1"he 

 mucous coat of the latter, and the internal furface of the 

 duel, are here contirmous. When we examine the opening of 

 the canal, we fee a fmall eminence, nearly of the fi/.e of a 

 pea, rounded, rather oblong, and divided in the middle ; 

 thrt^e is no valve, nor anv mufcular fibres arranged like a 

 fphinfter. The oblique courfe of the canal between tlie in- 

 teilinal coats prevents the paffage of the contents of the in- 

 teftine into the du£t, even when the inteftine is the nioft fully 

 diftended. The du6t is comprefTed whenever the gut is 

 filled, and more powerfully in proportion as the diftention is 

 greater. If the duodenum be inflated, and the duCl cut 

 through, no air efcapes. Ordinarily, too, we cann»t doubt 

 that the particular fenfibihty of the canal enables it to j-ejeft 

 matters tliat arc extraneous to it. 



Sometimes this duct does not receive the pancreatic. Ob- 

 fervations are recorded, in which it is faid to have opened 

 into the ftomach, and clofe to the pylorus ; but their cor- 

 rcctnefs is doubtful. 



The cyftic duft, of which we has'e mentioned the opening 

 into the Iiepatic, is a fliort canal, leading ft-om the latter tube 

 into the gall-bladder, and conveying into that receptacle a 

 portion of the bile, before it goes tO the duodenum. 



The gall-blaHd^r. — This bag does not exill in leveral genera 

 of the mammalia ; it has fometimes, but very rarely, been 

 deficient in the human fubjecl, without caufing any fenfible 

 derangement of funftions. Sometimes alfo there have been 

 two gall-bladders. 



It is placed obhquely, under the front of the great lobe of 

 the hver, in the excavation already defcribed, above the 

 colon and duodenum, to tke right of the horizontal filfure 

 and the lobulus quadratus, and in front of the right end of 

 the trasfverfe notch. Its moft ufual figure is pyriform ; 

 fometimes it is rather oval, or cylindrical. We remark in 

 it an external and an internal furface, an anterior extremity 

 called the fundus, a pofterior named the neck, and a middle 

 portion or body. The fundus, or large extremity of the gall- 

 bladder, is direfted forwards, a Httle to the right and down- 

 wards, and the fmall end backwards, to the left and up- 

 wards. But the direction varies confiderably according to 

 the attitude of the body. In the lupine potture the fundus 

 is higher than the neck ; the contrary is the cafe in lying on 

 the right fide. 



The external furface of the gall-bladder correfponds above 

 to the excavation in the right lobe of the liver ; this part has 

 been called the hepatic furface. Here it is not covered by 

 peritoneum, but adheres immediately to the proper mem- 

 brane of tlie liver, by means of a copious cellular fubftance, 

 containing numerous blood-veflels. Sometimes it has been 

 connected to the liver by a fmall kind of mcfentery, and 

 covered univerfally by peritoneum. The inferior part is 

 imooth, covered by peritoneum, and contiguous to the colon 



and firft ^rtioti of the duodenum ; it is called the loofe or 

 abdominal furface. 



The anterior extremity, or fundus, turned forwards, down- 

 wards and to the right Grounded, fmooth, and covered 

 partially or entirely by peritoneum. It correfponds to an 

 excavation in the anterior edge of the liver, and protrudes 

 more or lefs beyond this according to the quantity of bile it 

 contains. When it is empty, its fundus does not extend be- 

 yond this edge ; but, in the diftended ftate, it projects from 

 the liver, and is applied againft the abdominal parietes,' below 

 tlie middle of the cartilage of the fecond falfe rib. 



The neck, or pofterior extremity, which is directed rather 

 upwards and to the left, is bent upon itfelf, the convexity 

 of the curve lookiiig upwards, and the" concavity down, 

 wards. It is terminated by the cyftic duct, which, after a 

 courfe of about an inch and a half, unites with the hepatic 

 diict at a very acute angle. The internal furface of the gall- 

 bladder prefents a deep yellow or greenifti tint, according to 

 tlie colour of the bile ; indeed, all tliis excretory apparatus is 

 tinged after death in tlie fame manner, but not fo deeply as 

 the furface of the gall-bladder. Tiiis effect takes place verv 

 quickly after death : when the coats of the parts, that imme- 

 diately contain the bile, are coloured, tlie continuance of the 

 tranludation affefts all the neighbouring organs to a greater 

 or lefs dt^gree. This internal furface of the gall-bladder is 

 extremely irregular ; it is univerfally covered with rifiufj 

 lines, decuflating each other, and intercepting fmall areola; of 

 various figures. Thefe are again covered by other more mi- 

 nute hues, which divide the furface into ve.ry fmall fpaces. 

 Similar rifing lines, but more elevated, are found towards 

 the neck ot the gall-bladder, and throughout the cyftic 

 duft. The whole lurface of thefe parts, in confequence of 

 this ftrufture, exhibits a very beautiful rugous and cellular 

 appearance. Befides thefe ruga; of the internal coat, the 

 neck of the gall-bladder exhibits four or five tranfverfe femi- ■ 

 lunar folds, projecting into the cavity, and formed by du- 

 plicatures of the mucous coat. 



The capacity of the gall-bladder may be eftimated at about 

 one ounce. 



The cyftic dn£t is a contradted continuation of the neck 

 of the gall-bladder, about equal to a large crow-quill in dia- 

 meter. It forms at its commencement a remarkable turn, of 

 which the convexity is towards the livei* and the concavity 

 dow^nward. From the gall-bladder it firft afcends, then 

 makes this turn, and afterwards paftes downwards, between 

 the laminx of the little omentum, parallel and clofe to the 

 hepatic duct. After a courfe of about an inch and a half it 

 opens into that duiftat a very acute angle. The cyftic duct 

 has an irregular knotted appearance on its external furface, 

 which arifes from numerous femilunar folds, analoo-ous to 

 thofe at the neck of the gall-bladder, projecting into its ca- 

 vity, and very much narrowing its dimenfions. 



Two coats, a ferous and a mucous, compofe the gall- 

 bladder. The former, derived from the peritoneum., gives 

 only a partial covering to the organ. This membrane is 

 raifed from the hver, at the circumference of ilie Jeprefiioa 

 lodging the gall-bladder, and covers this vifcus cvjry where, 

 except at its adhefion to the furface of the hver. It is con- 

 tinuous below with the fuperior layer of the little omentum. 

 Tlie peritoneal coat is connected to the mucous by a tolera- 

 bly thick and uniform layer of cellular liffue, the cellular 

 coat of forae writers. Some firm and rather fnining threads, 

 moftly of a longitudinal direttion, are oblerved in this tiffue, 

 and liave been often con'.idered of a mufcular nature. The 

 blood-veffels and abforbcnts form a net-work in this cellular 

 fubftance, which fometimes contains a little fat. The inter. 

 Bb 2 r.a!, 



