Peritoneum block 5

1. PERITONEUM AND
MESENTERIES

7. Aorta
L
IVC
TrCol
SB
Ub
Ps

12. MESENTERY OVERVIEW

16. PERITONEUM
• Functions:
1. Minimize friction
2. Resist infection
3. Store fat
4. Pathway for
neurovascular
structures

17. PERITONEAL FLUID
• Derived from interstitial fluid of adjacent tissues
• Contains water, electrolytes, proteins, macrophages and
lymphocytes
• Peritoneum is a semi-permeable membrane that allows
fluid and cells to move in both directions
• Composition varies according to pathological condition
• Condition when there is excess fluid, usually due to
inflammation or infection is called ascites

18. PERITONEAL STRUCTURES
• Parietal and visceral layers – single layer of
peritoneum
• Mesentery – double layer that suspends gut tube, ie.,
dorsal mesentery and ventral mesentery
• Omentum – special type of mesentery that attaches
stomach to another structure, ie., greater omentum
and lesser omentum
• Peritoneal ligaments – double layer that attaches
more solid viscera to abdominal wall or other organs
• Peritoneal folds – raised, single layer of peritoneum
coursing over blood vessels and ligaments

19. MESENTERY

20. Dorsal Root of the Mesentery

21. Mesentery

22. VISCERAL PERITONEUM
• Intraperitoneal
– Organs nearly completely
surrounded by peritoneum
– Organs suspended by
mesentery, omentum or
ligament
• Retroperitoneal
– Organs only partially
covered by peritoneum
– Organs have no
mesentery

23. MESENTERY OVERVIEW

24. DORSAL
MESOGASTRIUM
28 days
• Rotation of stomach
causes dorsal
mesogastrium to balloon
out to left
• Creates the lesser sac or
omental bursa
48 days

25. DORSAL MESOGASTRIUM
• Splenorenal (lienorenal) ligament
• Gastrosplenic (gastrolienal) ligament

26. DORSAL MESOGASTRIUM –
GREATER OMENTUM

27. DORSAL MESOGASTRIUM –
GREATER OMENTUM

28. DERIVATIVES OF DORSAL
MESOGASTRIUM
• Greater omentum (gastrocolic ligament)
• Gastrosplenic ligament
• Splenorenal ligament

29. VENTRAL MESENTERY

30. VENTRAL MESENTERY
• Rotation of stomach moves liver and lesser omentum to right
• Falciform ligament remains in midline

31. GREATER AND LESSER SACES

32. VENTRAL MESENTERY – LESSER
OMENTUM
• Falciform ligament
Ligamentum teres
• Lesser omentum
Hepatogastric lig.
Hepatoduodenal lig.

35. DERIVATIVES OF VENTRAL
MESENTERY
• Falciform, coronary & triangular
ligaments
• Visceral peritoneum of liver
• Lesser omentum
– Hepatogastric ligament
– Hepatoduodenal ligament

36. MESENTERY PROPER
AND MESOCOLON

37. PERITONEAL FOLDS
• Median umbilical
fold – median
umbilical ligament
• Medial umbilical
folds – median
umbilical ligaments
• Lateral umbilical
folds – inferior
epigastrics

38. PARACOLIC GUTTERS
• Longitudinal channels running along medial and lateral sides of
ascending and descending colon
• Form where parietal peritoneum reflects onto colon as visceral
peritoneum

39. PARACOLIC GUTTERS

41. HEPATORENAL RECESS
RIGHT SUBHEPATIC RECESS
(MORRISON’S POUCH)
• One of the lowest
points in the
peritoneal cavity
• Excess fluid/blood will
pool in this area when
patient is supine

42. Summary
•
Dorsal Mesentery
•
•
•
•
•
•
•
Dorsal mesogastrium
Greater omentum
Gastrosplenic ligament
Lienorenal (splenorenal) ligament
Dorsal Mesoduodenum
Mesocolons (transverse and sigmoid)
Ventral Mesentery
•
•
•
Falciform ligament
Coronary and triangular ligaments
Lesser omentum - hepatogastric and hepatoduodenal ligaments