The peritoneum is a serous membrane that lines the abdominal cavity and viscera. It has two layers - the parietal layer lines the abdominal wall while the visceral layer lines the organs. The peritoneum forms folds called mesenteries that suspend parts of the gut and omenta that connect organs. Retroperitoneal organs like the kidneys are located outside the peritoneal cavity. The peritoneal cavity is divided into the greater and lesser sacs which communicate through the epiploic foramen. The peritoneum has clinical significance in procedures like peritoneal dialysis and can become inflamed, causing pain.

1. PERITONEUM
Dr. Anudeep singh
MBBS MD

2. Peritoneum—
A serous membrane lining the abdomen and is reflected over viscera.
2 layers: Parietal and Visceral.
Parietal–
• Lines the body wall.
• Develops from somatopleuric layer of lateral plate mesoderm
• Supplied by Somatic nerves and vessels.
• Sensitive to pain.
Visceral–
• Lines the viscera.
• Develops from splanchnopleuric layer of lateral plate mesoderm.
• Supplied by visceral vessels and autonomic nerves.
• Insensitive to pain, tactile and thermal sensations.

3. Terms:
• Mesentries (meso): folds of peritoneum suspending gut.
1. Mesentery- associated with parts of the small intestine.
2. Transverse mesocolon- associated with the transverse colon and
3. Sigmoid mesocolon- associated with the sigmoid colon.
• Omenta: folds of peritoneum connecting stomach and first part of
duodenum to other structures.
There are two:
1. The greater omentum: Derived from the dorsal mesentery;
2. The lesser omentum: Derived from the ventral mesentery.
• Peritoneal ligaments: two layered folds of peritoneum connecting
viscera.
• Intraperitoneal: Organs suspended in the cavity.
• Retroperitoneal: Organs outside the peritoneal cavity, with only one
surface or part of one surface covered by peritoneum.

5. Body wall
Peritoneum
(parietal layer)
Peritoneum
(Visceral)
Peritoneal cavity
Viscera
Abdominal aorta
Mesentery

6. Parietal peritoneum
Intra peritoneal organ
Peritoneal
ligament
Retroperitoneal organ
Mesentery
Visceral peritoneum
Body wall

7. Retroperitoneal organs
• Structures that lie behind the peritoneum are termed "retroperitoneal".
– Urinary
• Adrenal glands
• Kidneys
• Ureter
• Bladder
– Circulatory
• Aorta
• Inferior vena cava
– Digestive
• Esophagus
• Duodenum, pancreas, ascending and descending colon,
• Rectum (lower third is extraperitoneal)

8. • PNEUMONIC:
“SAD PUCKER”
• S = Suprarenal glands (aka the adrenal glands)
• A = Aorta/IVC
• D = Duodenum (Except first part)
• P = Pancreas (tail is intraperitoneal)
• U = Ureters
• C = Colon (only the ascending and descending colons)
• K = Kidneys
• E = Esophagus
• R = Rectum.

9. Peritoneal cavity
A potential space between visceral & parietal layers of peritoneum.
Thin amount of serous fluid present within the cavity, which has a
lubricating effect and allows free movement.
Divided into 2 inter-communicating sacs:
Greater sac – The larger one, begins superiorly at the diaphragm and
continues inferiorly into the pelvic cavity.
Lesser sac (Omental bursa)- The smaller one, posterior to the stomach
and liver.
Epiploic/omental foramen (foramen of Winslow): communication
between the two sacs.

10. Lesser Omentum
Hepatogastric ligament
Hepatoduodenal ligament

11. • Fold of peritoneum extending from:
- lesser curvature of stomach and first 2 cm of duodenum to the
liver.
2 parts: Hepatogastric and hepatoduodenal.
Contents:
• Hepatic artery proper.
• Portal vein
• Bile duct
• Lymph nodes and lymphatics and
• Hepatic plexus of nerves
• Right and left gastric vessels
• Gastric group of lymph nodes and
• gastric nerves.

12. Greater omentum
• Hangs like an apron from the
greater curvature of the
stomach.
• Made of 4 layers of
peritoneum
• 2nd and 3rd layers fuse to
obliterate the lesser sac
except about 2.5 cm below
greater curvature of stomach.
Contents:
• Right and left gastroepiploic
vessels
• Fat.

13. Liver
Lesser omentum
Stomach
Lesser
curvature
Greater
curvature
Greater
omentum

14. Omental (Epiploic) foramen
Bounded:
• Anteriorly: The portal vein,
hepatic artery proper, and bile
duct.
• Posteriorly: Inferior vena cava.
• Superiorly: Caudate lobe of the
liver.
• Inferiorly: first part of the
duodenum. Epiploic foramen

16. Vertical disposition

17. Rt. Triangular ligament
Median umbilical ligament
Umbilicus
Right triangular ligament

19. Structures formed by ventral mesogastrium:
•falciform ligament,
•Right and left triangular ligaments and
•Anterior and posterior layers of the coronary ligaments.

20. Liver
Falciform ligament
Lesser omentum
Stomach
Pancreas
Triangular ligaments being
Reflected onto diaphragm
Triangular ligaments
reflected onto diaphragm
Epiploic foramen

21. 1
2
3
4

23. Rectouterine
pouch
Utero vesical
pouch
Peritoneal reflection in female pelvis

24. Rectovesical
pouch
Peritoneal reflection in male pelvis

25. Horizontal disposition

26. Stomach
liver
Falciform ligament
Parietal peritoneum
Epiploic foramen
Gastroleinal
ligament
Leinorenal
ligament
Lesser omentum
Lesser sac
Greater sac
At the level of Epiploic foramen

27. Below the umbilicus

29. Duodenal Recesses
Close to the duodenojejunal junction, there may be four small pocketlike
pouches of peritoneum called the superior duodenal, inferior duodenal,
paraduodenal, & retroduodenal recesses.
Peritoneal recesses, which may be present in the region of the duodenojejunal junction. Note the presence of the
inferior mesenteric vein in the peritoneal fold, forming the paraduodenal recess.

30. Cecal Recesses
Folds of peritoneum close to the cecum produce three peritoneal recesses
called the superior ileocecal, the inferior ileocecal, and the retrocecal
recesses

31. The right & left
anterior subphrenic
spaces lie between the
diaphragm and the liver,
on each side of the
falciform ligament.
The right posterior
subphrenic space lies
between the right lobe
of the liver, the right
kidney, and the right
colic flexure .
Arrows show normal direction of flow of the peritoneal fluid from different
parts of the peritoneal cavity to the subphrenic spaces.
Subphrenic Spaces

32. Paracolic gutters
Present on medial and
lateral sides of ascending and
descending colons.
Right medial paracolic gutter:
Closed off from pelvic cavity by
mesentry.

33. Clinical
• Ventriculoperitoneal shunts:
In obstructive hydrocephalus CSF is drained into the peritoneal cavity
through a tube where it is absorbed.
• Peritoneal dialysis:
A small tube is inserted through the abdominal wall and dialysis fluid is
injected into the peritoneal cavity. Electrolytes and molecules are
exchanged across the peritoneum between the fluid and blood. Once
dialysis is completed, the fluid is drained.
• Peritonitis: Generalized inflammation of peritoneum- severe pain, card-
board ridgidity- Immediate laparotomy .
• Policeman of the abdomen: The greater omentum has the ability to
migrate to any inflamed area and wrap itself around the organ to wall off
inflammation.

34. • In recumbant position:
The most dependent parts of the peritoneum are the hepato-renal
pouch and the recto-uterine pouch in the females and rectovesical
pouch in males.
After operative procedures the patient is kept in propped up position
to encourage gravitation of peritoneal fluid in the pelvic cavity from
which absorption of infected fluid is less.
Hepatorenal pouch of morison
Rectouterine pouch of douglas