The peritoneum is a thin serous membrane that lines the abdominal and pelvic cavities and covers the organs within. It is derived from mesoderm. The peritoneal cavity is divided into the greater and lesser sacs. The peritoneum has several functions including movement of viscera, protection, and absorption. It is innervated by both autonomic and somatic nerves. The peritoneum forms several folds and structures that suspend organs, including the mesentery, transverse mesocolon, and greater and lesser omenta. It covers both peritoneal organs, which are attached via mesentery, and some retroperitoneal organs.

1. Peritoneum
To -MBBS 2ND Year
Dr Laxman Khanal
Assistant Professor (Department of Human Anatomy)
05-09-2016

2. For getting through annual
examination !!!

3. Q. Peritoneum derived from.
a. Ectoderm b. Mesoderm
c. Endoderm d. All three germ layer
Q. Peritoneal fluid is derived from.
a. Plasma b. Interstitial fluid
c. Plasma and interstitial fluid d. Intracellular fluid
Q. All of the peritoneal folds are double layered except.
a. mesentery b. Lesser omentum
c. Greater omentum d. Transverse mesocolon

4. Today’s objective
• To define peritoneum
• Formation and importance of peritoneum.
• To define peritoneal and retroperitoneal
organs.
• Define different modification of peritoneum.

5. Introduction
• The peritoneum is a thin serous membrane that
line the walls of the abdominal and pelvic cavities
and cover the organs within these cavities.
• Peritoneal cavity is the potential space between
the parietal and visceral layer of peritoneum.
• Cavity is divided into 2 main sacs- greater sac and
lesser sac.
• Small recesses of peritoneal cavity also present
which are separated from main cavity by fold of
peritoneum ( site for internal hernia).

7. Sex differences
in male
• Closed sac
• Lined by mesothelium or squamous epithelium
in female
•Its not closed sac , communicate through uterine tubes.
•Peritoneum covering the ovary is cuboidal epithelium.
•Peritoneum of the fimbria is lined by ciliated columner
epithelium.

9. Function
• Movement of viscera
• Protection of viscera
• Absorptive function- used for dialysis purpose
and Ventriculoperitoneal shunts.
• Regeneration
• Storage of fat
Normal amount of peritoneal fluid is 50 ml

10. Innervations
• Innervations of Parietal peritoneum is same as
that of body wall (intercostal nerve and phrenic
nerve). It is pain sensitive.
• Innervations of the Viscera peritoneum is same as
that of viscera ( autonomic nerve).
Pain of foregut referred to the Epigastric region
Pain of midgut to the umbilical region
Pain of hindgut to the hypogastric region

11. Division of peritoneal cavity
1. Greater sac
2. Lesser sac
1) Supra colic compartment
2) Infra colic compartment

12. Development of peritoneum

14. At the end of 3rd week lateral plate mesoderm split
into 2 layer, somatic layer and splanchnic layer.

15. Understand the path from retroperitoneal area to the peritoneal
area.

16. Ventral mesentery exists only in the region of the terminal
part of the esophagus, the stomach, and the upper part of
the duodenum, is derived from the septum transversum.

17. Relationship between viscera and
peritoneum
• Peritoneal organ
• Retroperitoneal organ
1. Primary
2. Secondary
 No organ found in peritoneal cavity.
 Mesentery hangs the peritoneal organ to the
body wall.
zygosis

18. • Duodenum-2nd and 3rd part
• Pancreas (except tail)
• Ascending colon
• Descending colon
• Upper rectum
Secondary
retroperitoneal organ

19. {Foregut
Mid gut and Hindgut

20. Lesser omentum
Falciform ligament

22. More caudal part forms the greater omentum

23. VDRL

25. Structures formed by peritoneum
• Omentum – Stomach
• Mesentery
• Transverse mesocolon
• Sigmoid mesocolon
• Meso appendix
• Ligaments
• Folds, recesses and fossa

26. Derivatives of ventral mesogastrium

34. Sigmoid mesocolon

35. • It is a broad fan shaped fold of
peritoneum which suspends the
coils of jejunum and ileum from
posterior abdominal wall.
• Root of mesentery is 15 cm long.
• Extends from D-J flexure to the
ileocaecal junction.
Mesentery

37. Mesoappendix
• Extends from terminal part of ileum to appendix.
• Appendicular artery runs in free margin of it.

39. Cont. in Peritoneum II