Peritoneum And Peritoneal Cavity

Question 1

What are the two layers of the peritoneum?

Answer 1

Parietal peritoneum - lines the walls of the cavity

Visceral peritoneum - covers the internal viscera

Question 2

What are the two layers of peritoneum derived from embryologically?

Answer 2

Parietal peritoneum - somatic mesoderm

Visceral peritoneum - splanchnic mesoderm

Question 3

What is the differences in the perception of pain in the parietal and visceral peritoneum?

Answer 3

Parietal peritoneal pain sensed by associated spinal nerves, and is well localised pain - sensitive to pressure, pain, temperature

Visceral peritoneal pain is sensed by the same visceral afferents that supply the viscera, therefore it is poorly localised pain, and referred to dermatomes - sensitive to stretch and chemical irritation

Question 4

What is the difference between an intraperitoneal organ and a retroperitoneal organ?

Answer 4

Intraperitoneal - enveloped in visceral peritoneum and suspended in the peritoneal cavity through mesenteries

Retroperitoneal - organs that are not associated with visceral peritoneum, only associated with parietal peritoneum on anterior surface. These organs lie outside of the peritoneal cavity

Question 5

What are the intraperitoneal organs?

Answer 5

Stomach, liver, spleen, small intestine (except distal 2/3rds of duodenum), transverse colon, sigmoid colon

Question 6

What are the retroperitoneal organs?

Answer 6

Suprarenal glands, aorta, duodenum (distal 2/3rds), pancreas, ureters, colon (ascending and descending), kidneys, oesophagus, rectum

Question 7

What primary and secondary retroperitoneal organs?

Answer 7

Primary retroperitoneal - organs that developed outside of the parietal peritoneum e.g, oesophagus, rectum, kidneys

Secondary retroperitoneal - organs that developed inside the peritoneum (initially intraperitoneal), and then their mesentery fused with the posterior abdominal wall e.g, ascending/descending colon

Question 8

What is the peritoneal cavity?

Answer 8

This is the potential space between the parietal and visceral peritoneum. It contains lubricating fluid which allows the organs of the abdominal to slide smoothly over each other

Question 9

What are the two divisions of the peritoneal cavity and where are they?

Answer 9

Greater sac - begins at the diaphragm and continues inferiorly to the pelvic cavity

Lesser sac (omental bursa) - lies posterior to the stomach and liver

Question 10

How are the greater and lesser sac connected?

Answer 10

Through the omental (epiploic foramen)

Question 11

What are the divisions of the greater sac?

Answer 11

Supracolic comparment 
Right Infracolic comparment 
Left infracolic comparment 
Right paracolic gutter
Left paracolic gutter

Question 12

What are the borders of the epiploic foramen (omental foramen)?

Answer 12

Anterior - heptaduodenal ligament
Posterior - inferior vena cava
Superiorly - caudate lobe of the liver
Inferior - superior part of the duodenum

Question 13

What is the hepatorenal recess?

Answer 13

Part of the peritoneal cavity which lies inferior to the liver and anterior to the kidney and suprarenal gland

Question 14

What is the subphrenic space?

Answer 14

Part of the peritoneal cavity which lies between the diaphragm and the liver

Question 15

What are the greater and lesser omentum?

What are they derived from embryologically?

Answer 15

Layers of visceral peritoneum

Greater omentum - derived from the dorsal mesentery
Lesser omentum - derived from the ventral mesentery

Question 16

Where is the greater omentum?

How many layers does it have?

Answer 16

Descends from 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 four layers of visceral peritoneum

Question 17

What is the function of the greater omentum?

Answer 17

Provides insulation to reduce hear loss
Contains acculturation of fat as an energy reserve
Role in immunity - can migrate to infected visceral (abdominal policeman)

Question 18

Where is the lesser omentum?

How many layers does it have?

Answer 18

Attaches from the lesser curvature of the stomach and proximal part of duodenum, and inserts onto the inferior surface of the liver

Question 19

What are the two parts of the lesser omentum?

Answer 19

Heptogastric ligament (medial) 
Hepatoduodenal ligament (lateral)

Question 20

What is located in the free edge of the hepatoduodenal ligament?

Answer 20

The portal triad:

• Hepatic artery proper
• Bile duct
• Portal vein

Question 21

What are the mesenteries derived from embryologically?

Answer 21

The dorsal mesentery

Question 22

What is ‘the mesentery’ and what are its attachments?

Answer 22

The mesentery is a large fan shaped double fold of peritoneum that connects the jejeunum and ileum to the posterior abdominal wall

Superior attachment - duodenojejunal junction
Inferior attachment - ileocecal junction

Question 23

What is the transverse mesocolon?

Answer 23

A fold of peritoneum that connects the transverse colon to the posterior abdominal wall

Question 24

What is the sigmoid mesocolon?

Answer 24

A V shaped fold of peritoneum that attaches the sigmoid colon to the posterior abdominal wall

Question 25

What are the umbilical ligaments and what are they remenants of?

Answer 25

Median umbilical ligament - remnant of embryonic urachus
Medial umbilical ligaments - remnant of fetal umbilical arteries
Lateral umbilical ligaments - overlie the inferior epigastric vessels