164 



NORMAL ANATOMY OF THE LIVER. 



an exabdominal tumour, and be uncovered ex- 

 cepting by the membranes of the ovum. But 

 the most interesting and unexplained form of 

 altered position is that in which the whole of 

 the viscera of the body are transposed, and the 

 liver becomes placed on the left instead of the 

 right side. These cases are generally perfect, 

 and the peculiarity does not seem to interfere 

 with the life or functions of the subject. The 

 liver presents its natural form and size, and 

 with the simple exception of left for right, pre- 

 cisely the same relations. The aorta, of course, 

 occupies the right side, and the venae cavae the 

 left, while the stomach is transferred to the 

 right. Sir Astley Cooper has preserved the 

 viscera of an adult who was the subject of 

 this transposition. And a few years since I 

 had the opportunity of examining a similar 

 case in the body of Smithers, a man who 

 was executed for committing arson accom- 

 panied with loss of life in Oxford-street. The 

 viscera of this man were perfectly healthy, the 

 liver finely formed, and the general fabric ro- 

 bust. 



The gall-bladder (fig. 33, 12,) (cystis 

 felleaj is a membranous sac of a pyriform 

 shape, situated in the shallow fossa upon the 

 under surface of the right lobe, and lying pa- 

 rallel with the longitudinal fissure. For con- 

 venience of description it has been customary 

 to divide it into a body, fundus, and neck 

 (cervix), although no precise mark of division 

 subsists between these parts. The body is the 

 middle portion ; the fundus the expanded ex- 

 tremity, which approaches the notch in the free 

 border of the liver, and frequently extends be- 

 yond it ; and the neck the narrow and taper- 

 ing portion of the sac which enters the right 

 extremity of the transverse fissure and forms 

 the cystic duct. 



The sac is in relation by its upper surface 

 with the substance of the liver, and by the 

 under part with the pylorus and ascending 

 duodenum. The fundus corresponds with the 

 right border of the rectus muscle, and may be 

 felt in that situation when filled with gall- 

 stones. 



The coals of the gall-bladder are three : 1. 

 an external or serous covering derived from the 

 peritoneum, which covers all that portion of 

 the sac which is not in contact with the sub- 

 stance of the liver. The gall-bladder is some- 

 times completely surrounded by the peritoneum, 

 and hangs loosely connected with the liver by a 

 duplicature of that membrane. 2. A fibrous 

 layer* (nervous) composed of cellulo-fibrous 

 tissue intermingled with tendinous fibres; and, 

 3. a mucous coat which lines the .interior of the 

 sac, and is continuous through the cystic and 

 hepatic ducts with the mucous lining of the 

 biliary structure of the liver, and through the 

 ductus communis choledochus with the mu- 

 cous membrane of the duodenum and ali- 

 mentary canal. The internal surface of the 

 mucous layer is raised into innumerable small 

 ridges and folds (ruga) by the ramifications of 

 the cystic artery and its capillaries, which give 



* In the ox, according to Monro, this coat is 

 distinctly muscular. 



to it a peculiarly reticulated appearance, and 

 the interspaces of the rugse are depressed into 

 numerous small muciparous follicles. In the 

 neck of the sac the mucous membrane is pro- 

 duced into from six to twelve small folds, 

 forming a kind of spiral valve by means of 

 which the bile is regulated in its descent into 

 the duodenum, and assisted in its entrance into 

 the gall-bladder. The existence of this pecu- 

 liar valvular apparatus gives to the neck of the 

 gall-bladder a sacculated appearance. The mu- 

 cous membrane is but loosely connected with 

 the fibrous coat, and the cystic artery with its 

 branches ramify between them. 



The excretory duct of the gall-bladder is the 

 cystic, (Jig. 33, 11); it is about an inch 

 and a half in length, and in diameter about 

 equal to the cylinder of a crow's quill. It is 

 generally somewhat tortuous in its course, and 

 appears sacculated from the continuation into 

 it of the spiral valve. Upon entering the 

 transverse fissure it unites with the excretory 

 duct of the liver, the hepatic duct, and the 

 junction of the two constitutes the ductus 

 communis choledochus. The ductus communis 

 choledochus, about three inches in length, des- 

 cends through the right border of the lesser 

 omentum, lying in front of the portal vein, and 

 to the right of the hepatic artery, and opens 

 into the duodenum by passing for some dis- 

 tance obliquely between its coats. It is united 

 to the other vessels in its course by the cellular 

 tissue of Glisson's capsule, and near to its ter- 

 mination is considerably constricted. 



The excretory ducts of the liver and gall- 

 bladder have three coats, an external or cellular 

 coat, a middle or fibrous, and an internal mu- 

 cous. A question exists among physiologists 

 as to the probable muscularity of the middle 

 coat in man; it is undoubtedly contractile, and 

 in some few instances of obstruction has pre- 

 sented an appearance very closely resembling 

 muscular fibres. Cruveilhier thinks the struc- 

 ture analogous to the dartos. In some animals, 

 as in the horse and dog, this coat is clearly 

 muscular. 



Varieties in the gall-bladder. The sac is 

 sometimes enormously dilated without any ap- 

 parent obstruction in its ducts. Occasionally 

 in acephalous and anencephalous foetuses it is 

 altogether absent. In a preparation now before 

 me of the liver of a foetus at the full period, 

 which lived for several hours after birth, and 

 which presented, in anatomical structure, several 

 peculiarities dependent upon arrest of de- 

 velopment, the most careful dissection has 

 failed to discover the slightest indication of 

 gall-bladder. Among the lower mammalia, as 

 in cats, a double or accessory gall-bladder is 

 by no means uncommon. Kiernan has ob- 

 served several instances of this variety. I my- 

 self have seen two, and have one at present 

 before me. In the kinkaju an accessory gall- 

 bladder is the normal character, and in the 

 liver of a small animal preserved by Hunter 

 in the Museum of the College of Surgeons, 

 there are three gall-bladders. 



Structure of the liver. The liver is com- 

 posed of lobules, of a connecting medium 



