Overview of peritoneal cavity and
peritoneal relations
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vertical disposition
Learning objectives
At the end of this lecture students should be able to:
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define peritoneum
understand the different folds of peritoneum.
discuss the embryological development of peritoneum and its fols
describe greater and lesser sacs
list the intra and retroperitoneal viscera
discuss vertical tracings of peritoneum
Peritoneum; Definition
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Peritoneum" is derived from Greek.
"Peri-" means "around", while "-ton-" refers to stretching.
Thus, peritoneuum means "stretched around" or "stretched over“.
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The peritoneum is a thin serous membrane that line the walls of the abdominal and pelvic
cavities and cover the organs within these cavities.
Peritoneum
Consists of two layers:
Parietal peritoneum
Lines the walls of the abdominal and pelvic cavities.
Visceral peritoneum
Covers the organs.
The epiploic foramen, greater
sac or general cavity (red) and
lesser sac,
or omental bursa (blue)
Peritoneal cavity
Is potential space between the parietal and visceral layer of peritoneum.
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In the male, is a closed sac.
But in the female, there is a communication with the exterior through the uterine tubes,
the uterus, and vagina
Peritoneal cavity
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It is filled with a small amount (about 50 ml) of slippery serous fluid that allows the two
layers to slide freely over each other
After invagination of viscera peritoneal cavity is reduced to a potential space.
Between two layers is serous fluid secreted by mesothelial cells.
Peritoneal cavity is divided in to greater sac and lesser sac.
Two sacs communicate with each other through epiploic foramen.
Peritoneal folds
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Some organs are mobile and are a suspended by folds of peritoneum providing mobility to
the organs and passage way to the vessels, nerves and lymphatics.
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Fold suspending small intestine is called mesentry.
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Fold suspending large intestine is called mesocolon.
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Fold attached to stomach is called omentum.
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Double layered folds connecting anterior abdominal wall and organs, or organs to each
other are called ligaments e.g. ligaments of liver and gastrosplenic ligaments.
Parietal peritoneum
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Lines inner surface of abdomen and pelvic walls and lower surface of diaphragm.
Loosely attached to the walls by extraperitoneal connective tissue.
Over expansile parts it is loose and cellular i.e. transversalis fascia and thick i.e. iliac fascia
psoas, fascia and pelvic fascia.
Is derived from somatopleural layer of mesoderm.
Pain sensitive.
Nerve supply is same as those of overlying body wall.
Visceral peritoneum
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Is derived from splanchnopleuric layer of lateral
mesoderm.
Lines outer surface of viscera.
Can not be striped.
Nerve supply is of those under lying viscera.
Mesentery ;
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The term mesentery is often used to refer to a double
layer of visceral peritoneum.
Intraperitoneal and
Retroperitoneal viscera
Intraperitoneal viscera
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Viscera are completely surrounded by peritoneum.
For example, stomach, superior part of duodenum, jejunum, ileum, caecum, vermiform
appendix, transverse and sigmoid colons, spleen and ovary.
Retroperitoneal viscera
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Are covered by peritoneum partially on their anterior surfaces only.
For example, kidney, suprarenal gland, pancreas, descending and horizontal parts of
duodenum, middle and lower parts of rectum, and ureter
Functions of peritoneum
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Provides slippery surface for movements of viscera.
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Contains various phagocytic cells which help in protection of viscera.
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Peritoneum is capable in storing large amount of fat.
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Mesothelial cells of peritoneum can transform into fibroblasts which promote healing
power.
The mesothelium acts as semi permeable membrane, metabolites like urea can be
removed from blood by artificially circulating fluids through peritoneal cavity, procedure is
called peritoneal dialysis.
Embryological development of Peritoneum
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Embryologically foregut is suspended by
mesenteries both ventrally and dorsally.
Ventral mesentry is called ventral
mesogastrium and dorsal mesentry is
called dorasal mesogastrium
Embryological development of Peritoneum
Ventral mesogastrium.
a. Ventral part forms
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1.Falciform ligament.
2.Right and left triangular ligament.
3.Superior and inferior coronary ligaments
b. Dorsal part forms lesser omentum.
Embryological development of Peritoneum
Dorsal mesogastrium.
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Greater or caudal part becomes greater omentum.
Spleen develops from cranial part of dorsal mesogastrium and divides it
into dorsal and ventral part ventral parts.
Ventral part forms gastrosplenic ligament while
Dorsal part forms the leinorenal ligament.
Cranial most part forms gastrophrenic ligament.
Mid gut and hind gut only have dorsal mesentery.
Omentum
Two-layered fold of peritoneum that extends from stomach to adjacent organs.
Greater omentum
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Four-layered fold of peritoneum, the anterior two layers descend from the greater
curvature of stomach and superior part of duodenum and hangs down like an apron in
front of coils of small intestine, and then turns upward and attaches to the transverse
colon.
If an infection occurs in the intestine, plasma cells formed in the lymph nodes combat the
infection and help prevent it from spreading to the peritoneum.
Greater omentum
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Lesser omentum
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Two-layered fold of peritoneum which extends from porta hepatis to lesser curvature
of stomach and superior part of duodenum
Hepatogastric ligament
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Extends from porta hepatis to lesser curvature of stomach
Hepatoduodenal ligament
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Extends from porta hepatis to superior part of duodenum
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Contains common bile duct, proper hepatic artery and hepatic portal vein.
Epiploic foramen
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Behind the right border of hepatoduodenal
ligament
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Superiorly caudate lobe of liver
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Inferiorly superior part of duodenum
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Anteriorly hepatodudenal ligament
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Posteriorly peritoneum covering the inferior
vena cava
Vertical tracings of peritoneum
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Peritoneum from anterior abdominal wall lines the anterior and posterior surface of liver
except bare area.
Anterior layer and posterior layer forms anterior and posterior layers of lesser omentum
extending from liver to lesser curvature of stomach.
Anterior layer then covers anterior surface of stomach and then forms anterior layer of
greater omentum (first layer of greater omentum) then becomes fourth layer of greater
omentum.
Vertical tracings of peritoneum
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Posterior layer lines posterior surface of stomach and forms second and third layer of
greater omentum and then lines upper part of posterior abdominal wall.
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Anterior layer then passes around the colon to become its posterior layer.
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Lines posterior abdominal wall.
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Anterior layer of mesentry then passes around small intestine to become posterior layer.
Vertical tracings of peritoneum
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Then peritoneum lining posterior abdominal wall descends in to pelvis
In female passes in front of rectum and uterus forming rectouterine pouch and from
uterus to urinary bladder and forms vesicouterine pouch.
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In male it passes in front of rectum to urinary bladder and forms rectovesicular pouch.
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Peritoneum passes from urinary bladder to anterior abdominal.
Vertical tracings of peritoneum
Vertical tracings of peritoneum
Blood Supply of the Peritoneum
To the parietal peritoneum
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Lumbar vessels
Branches of the inferior and superior epigastric arteries
Musculophrenic artery
Deep circumflex arteries
To the visceral peritoneum
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From the arteries supplying the appropriate viscera
Nerve Supply to the Peritoneum
To the parietal peritoneum
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From the nerves supplying the adjacent body wall and diaphragm
To the visceral peritoneum
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Sympathetic nerves innervating the appropriate visceral
The receptors are sensitive to:
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Overdistension of the hollow viscera
Traction on the mesenteries which stretch the nerve plexus in the wall of the organ or
mesentery
Spasm of smooth muscle
Ischemia (inadequate blood supply)