الرحيم الرحمن الله بسم

Peritoneum

Objectives

• Define Peritoneum.• Enumerate its functions.• Explain the general organization of the peritoneum.• Distinguish between Intraperitoneal and Retroperitoneal

Structures.• Describe Peritoneal Ligaments.• Define lesser and greater omenta.• Understand the location of epiploic foramen. • Discuss mesentery and mesocolon.• Explain the Peritoneal sacs.

PeritoneumIs a double-layer serous membrane.1.Parietal layer: lines abdomino pelvic wall & foldsback on itself forming a doubleMembrane: mesentery Functions of mesentery:-(1)Provides support: Intestines: Mesentery & Mesocolon. Stomach: Omenta. Liver: Falciform ligament.(2) Prevents intestinal twisting(3) Stores fat(4) Pathway for vessels & nerves2. Visceral Layer: covers the organs.Peritoneal cavity:Potential space containing a bit of serous fluid.

The Peritoneum

The parietal peritoneum

The visceral peritoneum

The peritoneal cavity

The visceral peritoneum

The peritoneal cavity

Peritoneum in sagittal section

Peritoneum in transverse section

Peritoneal versus Retroperitoneal (transverse section)

• Most of the internal organs are surrounded by visceral peritoneum: INTRAPERITONEAL Structures.

• Some organs (e.g. kidneys) are between peritoneum on one surface, and the body wall on the other: RETROPERITONEAL Structures.

Peritoneal versus Retroperitoneal (sagittal section)

kidneys

ureters

suprarenal glands

duodenum

pancreas

aorta

inferior vena cava

nerves

ascending colon

descending colon

The retroperitoneal Structures

Peritoneal ligaments, Omenta & Mesenteries• Peritoneal ligaments:

Two layers fold of peritoneum that connect solid viscera to the abdominal walls, e.g. Falciform ligament, Triangular ligaments & Coronary ligaments of the liver.

• Omenta:

Two layers fold of peritoneum that connect the stomach to another viscus, e.g. greater & lesser omenta.

• Mesenteries:

Two layers fold of peritoneum connecting parts of the intestine to the posterior abdominal wall, e.g. mesentery of small intestine, transverse mesocolon, sigmoid mesocolon.

Peritoneal folds related to the stomach

• The greater omentum:

• Lies between the Stomach and the anterior abdominal wall.

Peritoneal folds related to the stomach

• The lesser omentum Passes from the lesser

curvature of the stomach and first part of the duodenum to the inferior surface of the liver.

Greater omentum

Peritoneal folds related to the stomach and Kidney

• The gastrosplenic (gastrolienal) ligament:

Passes from the greater curvature of the stomach to the spleen.

• Splenorenal (lienorenal) ligament:

Connects the spleen to the posterior abdominal wall over the left kidney.

• The gastrophrenic ligament :

Connects the superior part of the greater curvatureof the stomach to the diaphragm.

Peritoneal folds related to the Stomach

Peritoneal folds related to the Liver• The Falciform ligament:

Passes from the parietal peritoneum on the anterior abdominal wall to the visceral peritoneum on the surface of the liver.

• The round ligament of the liver (ligamentum teres hepatis):

• Is the obliterated umbilical vein and it is found in the inferior free margin of the Falciform ligament.

• Coronary ligament:

Attaches the liver to the diaphragm. Two peritoneal ligaments are parts of the coronary ligament:

1. Left triangular ligament:

Is between the left lobe of

the liver and the diaphragm.

2. Right triangular ligament:

Is between the right lobe of

the liver and the diaphragm.

Peritoneal folds related to the Liver

Mesentery of the small intestine

• The mesentery suspends the jejunum and ileum from the posterior abdominal wall.

• Mesoappendix: Attaches the appendix to the posterior abdominal wall and it contains the appendicular artery.

Peritoneal folds & ligaments of colon• Transverse mesocolon:

Attaches the transverse colon to the posterior abdominal wall.

• Phrenicocolic ligament: Attaches the left colic flexure to the diaphragm.

• Sigmoid mesocolon: Suspends the sigmoid colon from the posterior abdominal wall.

Peritoneal sacs• Peritoneal structures all are

found within a subdivision of the peritoneal cavity called the greater peritoneal sac. Posterior to the stomach and lesser omentum is a smaller subdivision of the peritoneal cavity called the lesser peritoneal sac (omental bursa).

• The omental foramen (epiploic foramen, foramen of Winslow) connects the greater and lesser peritoneal sacs.

The Omental foramenBoundaries:• Anterior: Hepatic portal vein,

hepatic artery and bile duct contained within the lesser omentum.

• Posterior: Inferior vena cava & right crus of the diaphragm covered with parietal peritoneum.

• Superior: Caudate lobe of the liver covered with visceral peritoneum.

• Inferior: First part of the duodenum covered with visceral peritoneum.

2. Lesser and Greater Omenta

Lesser and Greater Omenta

Lesser Omentum

hepatogastric ligament hepatoduodenal ligament

the epiploic foramen(of Winslow)

Greater Omentum

3. The mesenteries

The mesenteries

transverse mesocolon

sigmoid mesocolon

mesentery of the small intestine

Contents ?

Lesser Sac

The supra-colic compartment

Rt. anterior subphrenic space Lt. anterior subphrenic space

Rt. posterior subphrenic(Rt. Subhepatic)

Morison’s pouch

left subhepatic Space(Lt. posterior subphrenic)

Nerve supply to the peritoneum

The parietal peritoneum phrenic nerve intercostal

first lumbar nerves obturator nerve

The visceral peritoneum autonomic

39