2. Introduction :
Greek peritonaion = stretch around
The peritoneum is a continuous serous membrane which
lines the abdominal cavity and covers the abdominal
organs .
It acts to support the viscera, and provides a pathway for
blood vessels and lymph..
The total membrane area includes the visceral
peritoneum (60%) , peritoneal covering the mesentery
and omental surfaces (30%) and the parital
peritoneum (10%)
3. Histology :
The peritoneal membrane is
comprised of six layers
consisting of the
1- capillary fluid film,
2- capillary endothelium,
3- endothelial basement
membrane
4- interstitium,
5- mesothelium
6- the fluid film .
N.B : mesothelium :consist of a
layer of simple squamous
epithelial cells
4.
5. Parts of peritonium
The peritoneum consists of :
A- the parietal peritoneum
a heterogeneous, serous, semi-permeable membrane that
lines the abdominal wall
B- the visceral peritoneum
which covers the abdominal organs
C- Peritoneal cavity
Its surface area is approximately 1-2 m2
In males, the peritoneum is a closed-sac system, whereas in
females it is an open-sac system with the fallopian tubes
and ovaries connecting to the peritoneal cavity
6. 1- Parietal Peritoneum :
The parietal peritoneum lines the
internal surface of the
abdominopelvic wall.
It is derived from somatic
mesoderm in the embryo.
It receives the same somatic nerve
supply as the region of the
abdominal wall that it lines,
therefore pain from the parietal
peritoneum is well localised and it
is sensitive to pressure, pain,
laceration and temperature.
The parietal peritoneum derives its
blood supply from the abdominal
wall (lumbar, intercostals, and
epigastric regions) and drains into
the inferior vena cava, while
7. 2- Visceral Peritoneum :
The visceral peritoneum invaginates to cover the majority
of the abdominal viscera.
It is derived from splanchnic mesoderm in the embryo.
the visceral peritoneum receives its blood supply from the
superior mesenteric artery and drains into the portal
vein. The total peritoneal blood flow ranges from 50–150
mL/min.
The visceral peritoneum has the same nerve supply as the
viscera it invests. Unlike the parietal peritoneum, pain from
the visceral peritoneum is poorly localised and is only
sensitive to stretch and chemical irritation.
8. 3- Peritoneal Cavity :
The peritoneal cavity is a potential
space between the parietal and visceral
peritoneum. It contains a small amount
of lubricating fluid.
The peritoneal cavity located between
the parietal and visceral peritoneum2,
contains approximately 100 mL of serous
fluid1 and becomes the dialysate
compartment during peritoneal dialysis
(PD) from which exchange of solutes
with the blood can occur.
The peritoneal cavity is divided broadly
in to parts :
A- Greater sac : main large part
B- Lesser sac small part situated
behined stomach , lesser omentum &
liver
C- two sac communicated through the
epiploic foramen (of winslow)
9. Drainage of the peritoneal cavity is mainly
accomplished by the lymphatic system.
Importantly, the subdiaphragmatic lymphatic system
is responsible for 70-80% of the lymphatic flow from
the peritoneal cavity.
The lymphatic system also serves as a pathway for the
removal of foreign substances and macromolecules.
In stable patients undergoing PD, the rate of
lymphatic flow varies from 7-20 mL/hr with total fluid
losses between 60-91 mL/hr3.
10. Structures which are formed by
peritoneum
1- Omentum:
The omentum is a double layer of peritoneum that extends from the
stomach and proximal part of the duodenum to other abdominal
organs.
A- Greater Omentum:
The greater omentum consists of four layers of peritoneum. It descends
from the greater curvature of the stomach and proximal part of the
duodenum, then folds back up and attaches to the anterior surface of
the transverse colon.
It has a role in immunity and is sometimes referred to as the
‘abdominal policeman’ because it can migrate to infected viscera.
11. B- Lesser Omentum :
The lesser omentum is considerably
smaller and attaches from the lesser
curvature of the stomach and the
proximal part of the duodenum to
the liver. It consists of two parts:
the hepatogastric ligament and the
hepatoduodenal ligament.
C- Omental foramen :
Behined the right border of
hepatoduodenal ligament
Superior- caudate lobe of liver
Inferior – superior part of
duodenum
Anterior-hepatodudenal ligament
Posterior-peritoneum covering the
inferior vena cava
12. 2- Mesentery
A mesentery is double layer of visceral
peritoneum.
It connects an intraperitoneal organ to
the (usually) posterior abdominal wall.
It provides a pathway for nerves, blood
vessels and lymphatics from the body
wall to the viscera.
Mesentery related to the
gastrointestinal system is named
according to the viscera
A- Mesoappendix : trianguler mesentery
from ileum to appendix
B- Transverse mesocolon : transverse
colon to posterior abd wall
C- sigmoid mesocolon inverted v shaped
with apex located in front of left ureter
and division of common iliac artery
13. 3-Peritoneal Ligaments
A peritoneal ligament is a double fold of peritoneum that
connects viscera together or connects viscera to the
abdominal wall, for example the hepatogastric ligament
which connects the liver to the stomach.
A- Ligament of liver :
1- Falciform ligament of liver
2- coronary ligament :
3- left and right trianguler ligaments
4- hepatogasteic ligamint
5- hepatoduodeenal ligament
6- ligamentum tereshepatis
17. Peritoneal subdivisions
The transverse colon and transverse mesocolon divides the great sac into :
1- supracolic compartment:
lie between diaphragmatic and transverse colon and transverse mesocolon
B- suprahepatic recess :
C- Lt supra hepatic recesses :
D- Rt supra- hepatic recesses
E- infra hepatic recess ‘
2- infra colic compartment :
A- Rt para colic sulcus
B- Lt para colic sulcus
C- Rt mesentric sinus
D- Lt mesentric sinus
18. Function of the Peritoneum
1- Movement of viscera
A- permits peristalsis of stomach and intestine
B- Abdominal movement during respiration
C- free movement of abdominal viscera
2- Protect of viscera :
A- Gaured against infection by phagocyte
B- provide celluler & humeral immuonological defense
C- greater omentum has the power to move towards site of
infection ((policeman of abdomen ))
19. 3- Absorption :
- It can absorb fluid effusion to blood capillaryies
- The greater absorptiove power of the subpherenic area
due to large surface area and respiratory movement
4- Dialysis :
Metabolices like urea can be removed from the blood in
PD
