This presentation was made for the purpose of understanding the embryology and histology of the liver as it would relate to hepatic failure

1. Embryology
and Histology
of the Liver
Edited by:
Std Dr. Orlando
Joseph
Course: General
Pathology
School: Georgetown
American University
1

2. Embryology of the Liver and Biliary
Apparatus
2

3. Overview
3

4. Alimentary System
 The liver is part of the alimentary system consisting of digestive tract(mouth to
anus) associated glands and organs and endoderm.
 During the 3rd and 4th weeks, cephalocaudal and lateral folding of the embryo
converts the trilaminar germ disc into an elongated cylinder, and the resulting
endodermal gut tube consists of the cranial foregut, a midgut open to the yolk sac
via the vitelline duct, and a hindgut
 The endoderm of the primordial gut forms most of the gut, epithelium, and glands.
 The primordial gut is initially closed at its cranial end by the oropharyngeal
membrane and at its caudal end by the cloacal membrane
 The foregut is the region that will give rise to the liver and biliary apparatus
4

5. 5
Development of the Germ
Layers

6. 6
A, Transverse view of a 4-week embryo showing the relationship of the
primordial gut to the omphaloenteric duct.

7. Liver& Biliary Apparatus
 The liver, gallbladder, and biliary
duct system arise as a ventral
outgrowth, the hepatic
diverticulum, from the distal part
of the foregut early in the fourth
week
 The diverticulum extends into
the septum transversum, a mass
of splanchnic mesoderm
separating the pericardial and
peritoneal cavities. The septum
forms the ventral mesogastrium in
this region.
 The hepatic diverticulum enlarges
rapidly and divides into two parts
as it grows between the layers of
the ventral mesogastrium, or
mesentery of the dilated portion of
the foregut and the future stomach.
 The larger cranial part of the
hepatic diverticulum is the
primordium of the liver ; the smaller
caudal part cystic diverticulum7

8.  The proliferating endodermal cells
form interlacing cords of hepatocytes
and give rise to the epithelial lining of
the intrahepatic part of the biliary
apparatus.
 The hepatic cords anastomose
around endothelium-lined spaces, the
primordia of the hepatic sinusoids.
 The fibrous and hematopoietic tissue
and Kupffer cells of the liver are
derived from mesenchyme in the
septum transversum.
 The liver grows rapidly from the 5th to
10th weeks and fills a large part of the
upper abdominal cavity The quantity
of oxygenated blood flowing from the
umbilical vein into the liver determines
the development and functional
segmentation of the liver.
 Initially, the right and left lobes are
approximately the same size, but the
right lobe soon becomes larger.
8

9.  Hematopoiesis (formation and
development of various types of
blood cells) begins in the liver
during the sixth week, giving the
liver a bright reddish
appearance.
 By the ninth week, the liver
accounts for approximately 10%
of the total weight of the
fetus. Bile formation by hepatic
cells begins during the 12th
week.
 The small caudal part of the
cystic diverticulum becomes
the gallbladder, and the stalk of
the diverticulum forms the cystic
duct
 Initially, the extrahepatic biliary
apparatus is occluded with
epithelial cells, but it is later
canalized because of vacuolation
resulting from degeneration of
these cells.9

10.  The stalk of the diverticulum connecting the hepatic and cystic ducts
to the duodenum becomes the bile duct.
 The bile entering the duodenum through the bile duct after the 13th
week gives the meconium (intestinal discharges of the fetus) a dark
green color.
10

11. Biliary Development
 During week 7-8 the biliary development of the liver is formed from
the hepatic diverticulum by the ductal plate
 The ductal plate is a primitive biliary epithelium which develops in
mesenchyme adjacent to portal vein branches (periportal
hepatoblasts).
 During liver development it is extensively reorganized (ductal plate
remodeling) within the developing liver to form the intrahepatic bile
ducts (IHBD).
11

12. Ventral Mesentery
 The ventral mesentery, a thin, double-layered membrane gives rise
to:
 The lesser omentum, passing from the liver to the lesser curvature
of the stomach (hepatogastric ligament) and from the liver to the
duodenum (hepatoduodenal ligament)
 The falciform ligament, extending from the liver to the ventral
abdominal wall
 The umbilical vein passes in the free border of the falciform
ligament on its way from the umbilical cord to the liver. The ventral
mesentery, derived from the mesogastrium, also forms the visceral
peritoneum of the liver.
 The liver is covered by peritoneum, except for the bare area, which
is in direct contact with the diaphragm
12

13. 13
Median section of caudal half of an embryo at the end of
the fifth week, showing the liver and associated
ligaments. The arrow indicates the communication of the
peritoneal cavity with the extraembryonic coelom.

14. Formation of Alimentary system
14

15. Histology of the Liver
15

16. Parts of the Liver
 Basic Features
 Portal tract
 Portal triad
 Hepatic venule
 Hepatocyte
 Kupffer cells
 Hepatic cords and sinusoids
Histologic examination of the
Liver
 Hematoxylin and eosin stain
 Trichrome stain
 Reticular stain
 Periodic acid-Schiff
 Reticulin stain
 Prussian stain
 Immunohistochemistry
 Electron microscope
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 Classical Lobule
 Portal Lobule
 Acinus Lobule
Zones of the Liver
Liver Arrangements
 Periporal Zone(3)
 Intermediate Zone(2)
 Central Zone(1)

17. 17
Fetal Liver
Ductal Plate

18. 18
Islands OF Extramedullary
Hematopoiesis
Portal triad

19. Adult Liver
19

20. Liver Basic Features
20
Hepatic
Cords
Space of Disse
Kupffer cells
Portal triad
Terminal
Hepatic venule
Sinusoids
HepatocytesPortal Tract

21. Liver Stroma
21

22. Sinusoids and Cord
22

23. Space of Disse
23

24. 24

25. 25

26. Hepatocyte
26
Mitochondri
a
Glycogen
Plasma
membrane
Nucleolar
membrane
Nucleolus
Nucleus

27. 27
Classical Liver Lobule

28. Portal Lobule
28

29. Limiting Plate
29

30. Liver Acinus
30

31. Zones of Liver
31
Peri-Portal
Zone
Intermediate Zone
Central Zone
Bile Drainage
Blood Flow
Central Vein
Portal Vein
Bile Duct
Hepatic Artery

32. Bile and Blood flow of the liver
32

33. Liver Connective Tissue
33
Peri-Portal
Zone
Portal Vein
Bile Duct
Hepatic Artery
Portal Tract

34. Liver Reticular Tissue
34

35. Liver Reticulin Fibers
35

36. PAS Stain for Glycogen
36
Hepatocytes
Sinusoids
Glycogen rich

37. Gallbladder
37
Mucosa of GB
Rokitansky-Aschoff
sinuses

38. Biliary System
38
Bile ductule
Canal of Herings
Cholangiocytes

39. Bile Canniculi
39

40. References
 Moore.L.Keith PHD.Persuad.T.V.N.PHD.Torschia.G.Mark PHD.Developing Human.10th Edition.
Elsevier Inc. Chapter 11.Foregut.Dvelopmen of liver and biliary ducts,page271-218.
Douglas.F.Paulsen(PHD).Histology and cell biology examination and boards review.5th
edition.Mc.Graw Hill Medical.Langes.Chapter 16.Glands associated with the digestive
system.The liver and bile duct.page 234-238.
 The University of Utah Eccles Health Sciences Library.Mercer university school of medicine.
The Internet Pathology Laboratory or Medical Education.Anatomy and Histology.Normal
histology.tissue gallbladder and liver.Histology of the liver and gallbladder.Retrived from.
http://library.med.utah.edu/WebPath/HISTHTML/NORMAL/NORMAL.html
 The University of Western Australia. School of Anatomy and Human Biology.Blue
histology.Notes.accessory digestive glands.histology of the liver and gallbladder.retrived from
http://www.lab.anhb.uwa.edu.au/mb140/
 Southern Illinois University School of Medicine.gastrointestinal system.Liver and gallbladder,bile
duct,bile canniculi.retrived .Histology of the liver and biliary system and gallbladder.retrived from
http://www.siumed.edu/~dking2/erg/liver.htm.
 Dr. med. H. Jastrow.Electron micrscpoic atlas of cells,tiisues and organs in the
internet.Hepatocyte.Retrived from https://www.uni-
mainz.de/FB/Medizin/Anatomie/workshop/EM/externes/Wartenberg/Leber3.jpg
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