Stomatch emroyonic development

1. EmbryonicNormal
Development of Stomach,
Liver, Pancreas and
Gallbladder
Falak Sher (22-Arid-2732)
Umair Ashfaq (22-Arid-1637)
Sheharyar Imtiaz (22-Arid-1633)
Hanzila Aftab (22-Arid-1597)

2. EMBRYONIC NORMAL
DEVELOPMENT OF STOMACH
Falak Sher (22-ARID-2732)

3. Common Steps of Stomach
Development
 In early embryological development,
stomach can be seen as a fusiform
dilation of caudal part of the foregut . It
is attached to the dorsal abdominal wall
by the dorsal abdominal mesogastrium ,
and to the ventral wall by the ventral
mesogastrium

4. Cont...
 Dorsal region of the stomach grows at
faster rate than ventral region. Due to
this, it changes morphologically, resulting
in the formation of a greater dorsal
curvature and lesser ventral curvature .At
cranial aspect of greater curvature, the
growth give rise to the fundus of a simple
Stomach.

5. Rotations of Stomach
 Stomach undergoes two rotations during
its development.
1-Longitudinal Rotation
2- Antero-Posterior Rotation

6. Longitudinal Rotation(1st Rotation)
 Stomach rotates clockwise at the angle of
90⁰ in such a way that left side moves to
the ventral position and right side moves
to the dorsal position. At this stage of
development, Stomach is C-Shaped,
flattened dorso-ventrally with greater
curvature and lesser curvature.

7. Antero-Posterior Rotation (2nd
Rotation)
 Stomach moves through an angle of 45⁰
in such a way that cardiac region moves
slightly downward and left side while
pyloric region moves upward and right
side. Hence, stomach gets its final
position and size in this way

8. Bovine Stomach Development
 The bovine stomach undergoes a complex
process of embryonic development,
resulting in the formation of several
distinct regions that play different roles in
the digestion of food. The development of
the bovine stomach can be broadly
divided into several stages, including
gastrulation, the formation of the
primitive gut tube, and the differentiation
of the stomach regions.

9. Overview of Embryonic
Development of Bovine Stomach
 Rumen:
The rumen is the largest
compartment of the bovine stomach. It
develops from the dorsal and left side of the
foregut. The rumen plays a crucial role in
the fermentation of ingested plant

10.  Reticulum:
The reticulum is located
caudal to the rumen and forms adjacent
to it. It develops from the ventral part
of the foregut. The reticulum functions
in the regurgitation and remastication
of food, aiding in the breakdown of
plant material.

11.  Omasum:
The omasum develops from the
caudal part of the foregut and lies to the
right of the rumen. It functions primarily
in the absorption of water, electrolytes,
and some fermentation products.

12.  Abomasum:
The abomasum, often referred to
as the "true stomach," is the most caudal region
of the bovine stomach. It develops from the
ventral part of the foregut. The abomasum
secretes gastric juices and enzymes, allowing for
the breakdown of proteins and further digestion.

13. Throughout embryonic development, the
different stomach regions continue to grow
and differentiate. After birth, the bovine
stomach undergoes further changes in
structure and function to accommodate the
transition from a milk-based diet to a diet
consisting primarily of plant material.

18. Umair Ashfaq (22-ARID-1637)

19. Embryology of Liver
 Organogenesis the development of the
organs take place from the third to the
eighth week during Embryogenesis.
 The derivatives or portions of the body
that develop from the Endoderm germ
layer include parts of the digestive tract,
the respiratory tract, the urinary tract
and the several internal organs.

20. Development of Liver
 The liver develops as a hollow ventral
diverticulum from the caudal region of
the foregut. The diverticulum divides into
two parts:
 Cranial (hepatic)
 Caudal (cystic)

21. Cont...
 The gallbladder, bile duct and liver begin
to develop 4th week of embryogenesis as a
ventral bud from the most caudal aspect
of foregut.
 This bud is called Hepatic Diverticulum
and it grows between the layers of Ventral
mesentry.

22. Components of Liver Formation
1
• Primitive Endoderm
• Foregut-Midgut junction
2
• Septum Transversum
• Hepatic Diverticulum
• Cystic Primordium
• Gallbladder
3
• Common bile duct
• Hepatic Ducts
• Liver/ Gallbladder

23. Cont...
 The Hepatic bud penetrates the Septum
Transversum.
 The Mesenchyme of Septum Transversum
induces this Endoderm to proliferate to
branch and to form the Glandular
Epithelium of the liver.
 The portion of Hepatic Diverticulum
continues to function as the Drainage duct
of the liver and the branch from this duct
produces the Gallbladder.

24. Cont...
 The Hepatic Endodermal cells undergo a
morphological transition from columnar
to Pseudostratified resulting in thickening
into the early Liver bud.
 Hepatic Stellate cells are derived from
Mesenchyme.

25. Embryological Development of various organs

26. Cont...
 After migration of Hepatoblasts into the
Septum transversum mesenchyme, the
hepatic architecture begins to be
established, with Liver sinusoids and bile
canaliculi appearing.
 The liver bud separates into the lobes.

27. Cont...
 The left Umbilical vein becomes the
Ductus venosus and the right Vitelline
vein becomes the Portal vein.
 The bipotential hepatoblasts begin
differentiating into Biliary epithelial cells
and hepatocytes.

28. .
The cells from cords (Line
of cells) which interact
with Vitelline and
Umbilical veins in Septum
Transversum to form the
Hepatic Sinusoids.
Hepatopoietic cells,
Kuffer cells and
Connective tissue from
Septum Transversum.

29. Functions of Liver
 From 2nd month of Gestation, embryonic
liver starts forming blood.
 Bile production starts at 12th week and
give dark colour to the meconium.
 The liver’s initial embryonic function is
cardiovascular as it is a Vascular
connection between Placental vessels and
Heart.

30. EMBRYONIC NORMAL
DEVELOPMENT OF
PANCREAS
Sheharyar Imtiaz (22-Arid-1633)

31. Pancreas
 The pancreas is J-shaped, lobulated, soft,
retroperitoneal organ.
 Its size is about 12-15cm.
 It is located transversely, a bit obliquely
on the posterior abdominal wall behind
the stomach.
 Its weight in adults is about 70-110 g.

32. Parts of Pancreas

33. Cont...
 Its development depends upon the
pancreas specific genes which then
decides the development of pancreas in
different time periods.
 Its development period varies from
species to species.
 Like in Human , it is developed just
prior 26 days of gestation.
 Like in different ruminants it is formed in
the third trimester.

34. The pancreas originates from two separate
endoderm diverticula, each of which elongates,
branches, and then forms acini in typical
glandular fashion.
 one diverticulum arises ventrally as a bud of
the hepatic diverticulum, it forms
the pancreatic duct and right lobe of the
pancreas
 the other diverticulum arises dorsally from the
duodenum (minor duodenal papilla) and forms
the accessory pancreatic duct and the left lobe
of the pancreas

36. o As the right and left lobes cross one another
during development, they fuse to from the body
of the pancreas; also, the duct systems
anastomose to form a common drainage
system.
o The endocrine (islet) cells of the pancreas also
develop from the endoderm of the diverticula.

39. Two outpouchings
of the Endodermal
linings of the
Duodenum
Ventral Bud
>> Lower part of
the head
>> Uncinated
Process
Dorsal Bud
>> Upper part of
the head
>> Neck
>> Body & Tail
Summary : Development of Pancreas
 Week 7 to20- Pancreatic hormones secretion increases, small amount maternal
insulin.
 Week 10- Glucagon (alpha) differentiate first, Somatostatin (delta), insulin (beta) cells
differentiate, insulin secretion begins.
 Week 15- Glucagon detectable in fetal Plasma.

40. EMBRYONIC NORMAL
DEVELOPMENT OF
GALLBLADDER
Hanzila Aftab (22-ARID-1597)

41. Definition of the Gallbladder
 In vertebrates, the gallbladder, also
known as the cholecyst, is a small
hollow organ where bile is stored and
concentrated before it is released into
the small intestine. In humans, the pear-
shaped gallbladder lies beneath the liver,
although the structure and position of the
gallbladder can vary significantly among
animal species

42. Cont...
It receives and stores bile, produced by the
liver, via the common hepatic duct, and
releases it via the common bile duct into
the duodenum, where the bile helps in the
digestion of fats.

43. Structure of the Gallbladder
 The gallbladder is a hollow organ that
sits in a shallow depression below the
right lobe of the liver, which is grey-blue
in life. In adults, the gallbladder
measures approximately 7 to 10
centimeters (2.8 to 3.9 inches) in length
and 4 centimetres (1.6 in) in diameter
when fully distended. The gallbladder
has a capacity of about 50 millilitres (1.8
imperial fluid ounces)

44. Cont...
 The gallbladder is shaped like a pear,
with its tip opening into the cystic duct.
The gallbladder is divided into three
sections: the fundus, body, and neck.
The fundus is the rounded base, angled so
that it faces the abdominal wall.
The body lies in a depression in the
surface of the lower liver. The neck tapers
and is continuous with the cystic duct,
part of the biliary tree.

47. Embryonic Development of
Gallbladder
 The gallbladder develops from
an endodermal outpouching of the
embryonic gut tube.
 Early in development, the human embryo
has three germ layers and abuts an
embryonic yolk sac. During the second
week of embryogenesis, as the embryo
grows, it begins to surround and envelop
portions of this sac.

48. Cont...
The enveloped portions form the basis for
the adult gastrointestinal tract. Sections of
this foregut begin to differentiate into the
organs of the gastrointestinal tract, such as
the esophagus, stomach, and intestines.

49. Cont...
 During the fourth week of embryological
development, the stomach rotates. The
stomach, originally lying in the midline of
the embryo, rotates so that its body is on
the left. This rotation also affects the part
of the gastrointestinal tube immediately
below the stomach, which will go on to
become the duodenum.

50. By the end of the fourth week, the developing
duodenum begins to spout a small outpouching
on its right side, the hepatic diverticulum, which
will go on to become the biliary tree. Just below
this is a second outpouching, known as the cystic
diverticulum, that will eventually develop into
the gallbladder

52. Gallbladder Removal
 A cholecystectomy is a procedure in
which the gallbladder is removed. It may
be removed because of recurrent
gallstones and is considered an elective
procedure. A cholecystectomy may be
an open procedure, or
a laparoscopic one.

53. In the surgery, the gallbladder is removed
from the neck to the fundus, and so bile will
drain directly from the liver into the biliary
tree. About 30 percent of patients may
experience some degree
of indigestion following the procedure,
although severe complications are much
rarer. About 10 percent of surgeries lead to
a chronic condition of postcholecystectomy
syndrome.

54. Other Animals
 Most vertebrates have gallbladders, but the
form and arrangement of the bile ducts may
vary considerably. In many species, for
example, there are several separate ducts
running to the intestine, rather than the
single common bile duct found in humans.
Several species of Mammals (including
Horses, Deer, Rats and Laminoids),
several species of birds lampreys and all
invertebrates do not have a gallbladder.

55. Cont...
The bile from several species of bears is
used in traditional Chinese medicine; bile
bears are kept alive in captivity while their
bile is extracted, in an industry
characterized by animal cruelty.