الفهرس 
Introduction
Lobation of liverOnly 14 pages are availabe for public view
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Abstract
Summery and conclusion
The present study was carried out on 50 chick embryo of
Dandarawi chicken collected from Assiut university farm at a 3, 5, 7, 9,
11, 13, 15, 17 and 19 day of prehatching life.
At 3 day, the hepatic diverticulum gives dorsal and ventral parts
in relation to the ductus venosus. At 7th day, the dorsal and ventral parts
become the left and right lobes respectively where the gall bladder
located on visceral surface of the right lobe and a transverse fissure
dividing the left lobe into dorsal and ventral parts. At 9th day, the right
lobe is longer and higher than the left one where the right lobe is contact
dorsally with the mesonephros and the left one is separated from the
mesonephros by the glandular stomach. At 11th day, the caudal vena cava
crossing the lateral part of the right lobe. The interlobar fissure is
occupied mainly by the umbilical vein. At 13th day, the parietal surface
of the two lobes is related to the heart and body wall but visceral surface
of the left lobe is related to muscular stomach and that of the right lobe is
related medially to muscular stomach and laterally to the intestine and
gall bladder. At 15th day, the cranial end of the right lobe has three
processes dorsal, middle and ventral but the cranial end of the left lobe
has two processes dorsal and ventral.
Middle process appears at 11th day, and the middle process of the
right lobe more prominent and caudal to that of the left one, but their
relation differ as the middle process of the right lobe is located between
the gallbladder and portal vein dorsally and the umbilical vein ventrally.
The middle process of the left lobe is located ventral to the portal vein
only. At 13th day, right middle process is divided caudally.
At third day, the vitelline veins extend from the yolk sac to the
heart on either side of the hepatic diverticulum. Near the heart, the two
vitelline veins united together forming the ductus venosus which is
continued cranially with the sinus venosus and its caudal part is the
caudal vena cava.
At 7th day, the vitelline veins caudal to the liver anastomose
together forming the portal vein which gives off left portal branch to the
left lobe of liver and continue as right portal branch to the right lobe.
The gall bladder was observed in 5th day. In 7th day, it appears on
visceral surface of the right lobe. In 11th day, the gall bladder appears
dorsal to middle process of right lobe. In 13th day, it increases in size and
extends laterally there fore its neck and body are located dorsal to middle
process but fundus is lateral to it.
The duct system of the right lobe is hepatocystic and cystoenteric,
but that of the left is hepatoenteric duct.
At 7th day, the left and right dorsal hepatic cavities could be
observed but the ventral ones remain connecting with the plural cavity.
The dorsal hepatic cavity related dorsally to the lung but at 9th days due to
the appearance of the cranial thoracic air sacs the dorsal hepatic cavities
separating from the lung by these sacs. At 9th day the ventral hepatic
cavities are separated from the pleural cavities. At 9th day, as the dorsal
hepatic cavities are located craniodorsal to that of the ventral hepatic
cavities there for at the cranial end of the liver, the dorsal hepatic cavities
are only observed, at the level of the esophagus appear dorsal and ventral
cavities and at the level of the glandular stomach the ventral only
observed. At 13th day, the left dorsal hepatic cavity connected with the
intestinal coelomatic cavity but the right one is separated from the
intestinal cavity by a septum.
The dark cells increases in number on expanse to light cells. At 7th
day the light cells become numerous and then after the gradually decrease
to reach their minimum at 13th day, but at 15th day of incubation these
cells are difficult to be observed.
The width of the lumen of the sinusoid is reversely related to the
age of the embryo.
At 5th to 7th days of incubation, the mesothelium covering the liver
is flat to cuboidal and at 9th day becomes flattened.
Nucleus at 7th day is large, lightly stained and with two nucleolus
gradually become dark and small.
The hepatocytes increase in size gradually from 7th day to 19th day
of incubation. In apical border of hepatocyte, there are microvilli which
have maximum length at 7th day of incubation then decrease gradually
until 19th day of incubation. Also the bile canliculi is wide at 7th day of
incubation, it becomes narrow and reaching the narrowest level at 19th
day of incubation.
The lipid increases gradually from 7th day to gain its maximum at
the 19th day.
The mucopolysaccharide begins to increase gradually to gain its
maximum at 9th day then after it reaches the lowest level at 11th day then
increases in 13th day and continues at this level till end of incubation.