WINDSOR UNIVERSITYSCHOOL OF MEDICINE

Dr. SREEKANTH THOTA

DEPARTMENT OF ANATOMY

ABDOMEN

Peritoneum

Parietal and Visceral peritoneum Intra and retroperitoneal organs Peritoneal cavity

Peritoneum

A thin membrane (the peritoneum) lines the walls of the abdominal cavity and covers much of the viscera.

The parietal peritoneum lines the walls of the cavity and the visceral peritoneum covers the viscera.

Between the parietal and visceral layers of peritoneum is a potential space (the peritoneal cavity).

Parietal peritoneum and Visceral peritoneum

The parietal peritoneum is served by the same blood and lymphatic vasculature and the same somatic nerve supply as is the region of the wall it lines.

The visceral peritoneum and the organs it covers are served by the same blood and lymphatic vasculature and visceral nerve supply.

Intraperitoneal organs

Completely covered with visceral peritoneum (e.g., the stomach and spleen).

Retroperitoneal organs

Outside the peritoneal cavity, external, posterior, or inferior to the parietal peritoneum and are only partially covered with peritoneum (usually on just one surface).

Peritoneal Formations

Various terms are used to describe the parts of the peritoneum that connect organs with other organs or to the abdominal wall, and the compartments and recesses that are formed as a consequence.

1. Peritoneal ligaments 2. Omentum 3. Mesentery

Peritoneal ligaments

Consists of a double layer of peritoneum that connects an organ with another organ or to the abdominal wall.

The liver is connected to the: 1. Anterior abdominal wall by the

falciform ligament 2. Stomach by the hepatogastric

ligament 3. Duodenum by the hepatoduodenal

ligament

The stomach is connected to the:

1. Inferior surface of the diaphragm by the gastrophrenic ligament.

2. Spleen by the gastrosplenic ligament . 3. Transverse colon by the gastrocolic

ligament, the apron-like part of the greater omentum.

Omentum

Is a double-layered extension or fold of peritoneum that passes from the stomach and proximal part of the duodenum to adjacent organs in the abdominal cavity

1. Greater omentum 2. Lesser omentum

Greater omentum

Is a prominent peritoneal fold that hangs down like an apron from the greater curvature of the stomach and the proximal part of the duodenum.

After descending, it folds back and attaches to the anterior surface of the transverse colon and its mesentery.

Lesser omentum

Connects the lesser curvature of the stomach and the proximal part of the duodenum to the liver

Mesentery

Is a double layer of peritoneum that occurs as a result of the invagination of the peritoneum by an organ and constitutes a continuity of the visceral and parietal peritoneum.

It provides a means for neurovascular communication between the organ and the body wall

1. Small intestine mesentery is usually referred to simply as the mesentery

2.Transverse and sigmoid mesocolons 3. Mesoesophagus, Mesogastrium, and

Mesoappendix

Subdivisions of Peritoneal cavity Greater sac Lesser sac

Greater sac

The greater sac is the main and larger part of the peritoneal cavity.

A surgical incision through the anterolateral abdominal wall enters the greater sac.

Lesser sac (omental bursa )

The omental bursa (lesser sac) lies posterior to the stomach and lesser omentum.

The omental bursa communicates with the greater peritoneal sac through the omental foramen (epiploic foramen), an opening situated posterior to the free edge of the lesser omentum (hepatoduodenal ligament).

The omental foramen can be located by running a finger along the gallbladder to the free edge of the lesser omentum

The boundaries of the omental foramen are

1.Anteriorly: the hepatoduodenal ligament containing the portal vein, hepatic artery, and bile duct

2. Posteriorly: the IVC and right crus of the diaphragm

3. Superiorly: the liver, covered with visceral peritoneum

4. Inferiorly: the superior or first part of the duodenum

Walls and recesses of omental bursa

Clinical correlates

Paracentesis of the Abdomen

Paracentesis of the abdomen may be necessary to withdraw excessive collections of peritoneal fluid, as in ascites secondary to cirrhosis of the liver.

Under a local anesthetic, a needle or catheter is inserted through the anterior abdominal wall.

The underlying coils of intestine are not damaged because they are mobile and are pushed away by the cannula.

Ascites

Ascites is a gastroenterological term for an accumulation of fluid in the peritoneal cavity. The medical condition is also known as peritoneal cavity fluid, peritoneal fluid excess, hydroperitoneum .

Although most commonly due to cirrhosis and severe liver disease, its presence can exhibit other significant medical problems.

Abdominal paracentesis

Paracentesis of the abdominal cavity in midline (1) and laterally (2).