PERITONEUM

Question 1

Describe the organisation of the peritoneum.

Answer 1

• Serous membrane lining abdominal wall.
• Has 2 layers: parietal and visceral layer.
• Peritoneal cavity- cavity between parietal and visceral layers

simple squamous epithelium

Question 2

Discuss the formation, names and functions of peritoneal folds.

Answer 2

Formation
* Formed by visceral layer of peritoneum

Names
1. If attached to stomach- omentum(lesser and greater)
2. If attached to small intestine- mesentery
3. Large intestine- mesocolon
4. Liver and spleen- ligaments (falciform, coronary & triangular, gastrosplenic, lienorenal)

Functions
1. transmit vessles, nerves and lymphatics to supply the viscera.
2. allow mobility of organs.

Question 3

What is the blood supply and innervation of the peritoneum?

Answer 3

Parietal layer
* Blood and nerve supply is similar to the body wall.
* nerve supply: lower 6 thoracic nerves, L1(iliohypogastric and ilioinguinal), phrenic nerve to roof.
* sensitive to pain
* Blood supply- from those of the body wall
* Lymph drainage- join those of body wall

Visceral layer
* similar to viscera in nerve and blood supply
* nerve supply- autonomic nerves of related viscera.
* Sensitive only to stretch
* blood supply- from those of related viscera
* lymphatic drainage- join those of the related viscera.

Question 4

State the attachments,contents, and parts of the greater omentum

apron

Answer 4

Attachments
1. Anterior two layers descend from greater curvature of stomach

Contents
1. Adipose tissue
2. Milky spots- aggregation of macrophages
3. Right and left gastroepiploic vessels- run btn anterior and posterior layers close to greater curvature of the stomach.

Functions
1. store fat
2. protects peritoneal cavity- macrophages
3. Limits spread of infection
4. forms partition between supra and infracolic compartments of the greater sac.
5. Protects viscera

made of four layers

Question 5

State the attachments,contents, and parts of the lesser omentum.

Answer 5

Attachments
1. inferiorly- right side of abdominal esophagus, first part of duodenum and lesser curvature of the stomach.
2. superiorly- inverted L to the margins of porta hepatis and fissure for ligamentum venosum.

Parts
- part between stomach and liver is called hepatogastric ligameng and part between duodenum and liver is called hepatoduodenal ligament.

Contents
1. right and left gastric vessels and associated gastric lymph nodes
2. branches of the left gastric nerve
3. Portal vein
4. Hepatic artery and bile duct anterior to portal vein, duct on the right of the artery
5. autonomic nerves
6. lymphatic and lymph nodes

double layered

Question 6

Discuss the mesentery.

Answer 6

Root of mesentery(attached border)
* Attached to an oblique line across the posterior abdominal wall, extending from the duodenujejunal flexure to the iliocecal junction.
* The root from above downwards crosses in front of:
1. third part of duodenum
2. abdominal aorta
3. IVC
4. right gonadal vessels
5. right ureter
6. right psoas major
* divides the infracolic compartment into two parts- right and left
- right one is small and terminates in the iliac fossa.
- Left one is larger and passes without interruption into true pelvis.

Free border(intestinal)
* encloses ileum and jejunum
* accounts for the formation of pleats/folds
* permits free mobility of the loops of jejunum and ileum in abdominal cavity.
* has fat diposition- more in the distal part

Contents
1. superior mesenteric artery and vein- in the root
2. jejunal and ileal branches of superior mesenteric artery and accompanying veins.
3. lymphatics- lacteals
4. lymph nodes
5. autonomic nerve plexuses
6. fat and connective tissues
7. jejunum and ileum- enclosed in free border

Broad fan-shaped fold which suspends the coils of the small intestine from the posterior abdominal wall.

Question 7

Discuss the transverse mesocolon

Question 8

Discuss the sigmoid mesocolon

Question 9

Discuss the falciform ligament

Question 10

List the functions

Question 11

Describe the peritoneal cavity.