NORMAL ANATOMY OF THE LIVER. 
papille that is to be attributed the facility with 
which Scemmering and other anatomists in- 
jected the ducts from the arteries and veins, 
_and not to any direct communication between 
the vessels and the ducts.” 
The mucous lining of the ducts is provided 
vith a considerable number of muciparous 
follicles which mingle their secretion with the 
bile during its passage along the excretory 
‘tubes. These follicles have been described by 
ll anatomists as existing in the larger ducts, 
it they were not known to be present in the 
smaller branches until they were discovered and 
igured by Kiernan. In the larger ducts they 
irregularly dispersed, but in the smaller 
es are found arranged in two longitudinal 
WS upon opposite sides of the ducts. Hence 
e vascularity of the hepatic ducts is intended 
fo perform a higher function than the mere 
nutrition of those tubes; it provides an im- 
portant secretion as an auxiliary to the compo- 
sition of the bile. ; 
_ The hepatic artery arises from the celiac 
axis and ascends through the right border of 
the lesser omentum to the transverse fissure of 
the liver, where it bifurcates into two branches 
for the right and left lobes. The right and left 
epatic arteries ramify in the portal canals, and 
give off branches which accompany each twig 
of the portal vein and hepatic duct. Their 
Branches, like those of the vein and duct, are 
‘the vaginal, the interlobular, and the lobular. 
__ The vaginal arteries arise from the hepatic 
Bteries in the portal canals, and assist in form- 
ing the vaginal plexus in the capsule of Glisson, 
om which the interlobular branches are given 
off to accompany the interlobular portal veins 
and ducts. In the larger canals the plexus 
completely surrounds the portal vessels, but in 
he smaller canals the plexus is situated only 
On the side opposite to the cylinder of the 
artery, and in the tissue of Glisson’s capsule. 
This vaginal plexus has the effect of supplying 
the lobules which are the most distant from the 
vessel to which they belong, as certainly, as those 
which are in immediate contact with its cylin- 
ler. The vaginal arteries anastomose so freely 
with each other, that if the hepatic artery of 
one side be injected, the injection will return by 
that of the opposite side. 
_ The interlobular arteries enter the intervals 
of the lobules through the interlobular spaces 
and ramify upon the capsular surface of the 
obules. ey are distributed principally to 
the interlobular ducts, around which they form 
a vascular net-work. The question of the 
mosculation of these vessels is very difficult to 
lecide by dissection on account of their ex- 
treme minuteness; but analogy would lead us 
to infer that they must communicate. 
_ The lobular arteries, “ exceedinuly minute 
and few in number,” so as to be demonstrable 
with much difficulty in the structure of the lo- 
bules, enter the circumference of these bodies 
with the lobular ducts upon which they are 
distributed. They are the nutrient vessels of 
he lobules, and termivate in the lobular venous 
plexus formed by the portal vein. 
_ The mode of distribution of the hepatic ar- 
; 
171 
tery is a subject upon which some difference 
of opinion subsists between Miiller and Kier- 
nan. Kiernan states that the hepatic artery is 
distributed chiefly upon the coats of the ducts 
and gall-bladder, upon the coats of the other 
vessels to which it forms the vasa vasorum, and 
to the substance of the lobules. The ducts are 
highly vascular, and are abundantly supplied, 
the lobules sparingly, but ‘“ few” vessels, and 
those “ exceedingly minute,” being traceable 
into them. From the capillavies of the ducts 
and vessels, the blood having become venous 
during its circulation is returned into the portal 
vein, and thence conveyed onwards to the lo- 
bules, where it is distributed through the lobular 
venous plexus. The blood of the terminal 
lobular arteries also becomes venous in the 
substance of the lobules, and is likewise poured 
into the lobular venous plexus. So that, ac- 
cording to this author, the whole of the blood 
distributed through the hepatie artery is re- 
ceived by the portal vein, either in the course 
of that vessel, or at its termination in the lo- 
bular venous plexus, and therefore, that all the 
blood circulating through the plexus must ne- 
cessarily be venous. He likewise affirms that 
no part of the blood of the artery is poured 
directly into the hepatic vein. “The intra- 
lobular veins,” he says, “convey the blood 
from the lobular venous plexus, and not from 
the arteries.” These views are the results of 
the evidence of numerous experimental injec- 
tions. With regard to the vascularity of the 
lobules, he observes, “‘ These bodies cannot be 
coloured with injection from the artery, even in 
the young subject; in the adult, after the most 
successful injection, when the arteries of the 
cellular capsule, those of the excreting ducts 
and gall-bladder, and the vasa vasorum are mi- 
nutely injected, a few injected vessels only are 
detected entering the lobules. I have fre- 
quently tied the thoracic aorta in living animals, 
thereby cutting off all supply of blood from 
the abdominal viscera; and in these animals, 
when injected from the aorta below the ligature 
forty-eight hours after death, the integuments, 
the secreting portions of the kidneys, the spleen, 
pancreas, intestines, and pelvic viscera were co- 
loured in a remarkable degree by the injection ; 
on the surface of the liver a few vessels only 
could be discovered, this organ presenting a 
curious contrast with the surrounding coloured 
viscera. The gall-bladder and ducts were, how- 
ever, equally well injected with the intestines ; 
the vasa vasorum were also well injected.” 
Perceiving in the progress of his experiments 
that the injection thrown into the artery passed 
freely into the portal vein by means of the ca- 
pillary communication existing between these 
two vessels on the coats of the ducts, and 
through the vasa vasorum of the vessels, he 
imagined that the injected fluid might in this 
way be diverted from the lobules, and that this 
must be the cause of his want of success in 
filling the lobular arteries. To ascertain if such 
were the case, he injected the portal vein in the 
first instance with blue, and then the arteries 
with red. ‘“ On dissection, branches of the two 
sets of vessels were found in the coats of the 
