L3 : ABDOMINAL ORGANS & PERITONEUM
Abdomen
lower part of the trunk, below the diaphragm
division: abdomen proper, pelvis, perineum
Abdominal cavity
extends from lower part of the thoracic cage down into the bony pelvis as pelvic cavity
major contents:
peritoneum: serous membrane that lines the abdominopelvic cavity
parts of GIT tract ( stomach, small & large intestine, liver, pancreas )
spleen, suprarenal glands
parts of urinary system
large vessels ( abdominal aorta, common, external, internal iliac arteries, IVC)
,Peritoneum
serous membrane that lines the abdominopelvic cavity and surrounds the abdominal organ
SIMPLE SQUAMOUS EPITHELIUM
2 layers:
Parietal peritoneum – lines the abdominal & pelvic wall, inferior surface of diaphragm
Visceral peritoneum – lines the visceral organs
Both are separated by capillary film of peritoneal fluid
Many organs are suspended by peritoneum folds ( mobile organs )
Retroperitoneal organs are fixed and immobile organs on the posterior abdominal wall
Kidneys, esophagus, pancreas, adrenal glands, aorta, rectum, colon
Folds of peritoneum
I. Greater omentum
- double fold of peritoneum attached to the greater curvature of stomach & covers
the front of the abdomen
- connects the stomach & duodenum to the pancreas
- parts: Gastrocolic ligament, gastrosplenic ligament, gastrophrenic ligament
- function: “policeman of abdomen “ , protect from infection
II. Lesser omentum
- Double fold of peritoneum connecting lesser curvature of stomach and 1 st 2cm of
duodenum to the liver
, - Attachments: superiorly to portal hepatis & inferiorly to the lesser curvature of
stomach and duodenum
- Parts: Hepatogastric ligament & hepatoduodenal ligament
- RIGHT FREE MARGIN OF LESSER OMENTUM – Anterior boundary of epiploic foramen
- Contents: portal vein ( post), hepatic artery ( ant & left ), bile duct ( ant & right )
III. Mesentery proper
- Large, broad, fan-shaped fold of peritoneum attached to coils of jejunum and ileum
- Contents: jejunal & ileal branches of superior mesenteric artery & vein, lymph
nodes, CT
IV. Transverse mesocolon
- Broad fold of peritoneum that suspends the transverse colon from upper part of
post abdominal wall
- Attachment: to the anterior surface of head & anterior border of the body of the
pancreas.
- Contents: Middle colic vessels & lymphatics, trans colon
V. Sigmoid mesocolon
- Triangular fold of peritoneum
- Suspends the sigmoid colon with the pelvic wall
- Contents: Sigmoidal, superior rectal vessels, nerves
VI. Mesoappendix
- Fold of peritoneum around the
appendix, attached to ileocecal junction
- Contents: appendicular artery & vein
Abdomen
lower part of the trunk, below the diaphragm
division: abdomen proper, pelvis, perineum
Abdominal cavity
extends from lower part of the thoracic cage down into the bony pelvis as pelvic cavity
major contents:
peritoneum: serous membrane that lines the abdominopelvic cavity
parts of GIT tract ( stomach, small & large intestine, liver, pancreas )
spleen, suprarenal glands
parts of urinary system
large vessels ( abdominal aorta, common, external, internal iliac arteries, IVC)
,Peritoneum
serous membrane that lines the abdominopelvic cavity and surrounds the abdominal organ
SIMPLE SQUAMOUS EPITHELIUM
2 layers:
Parietal peritoneum – lines the abdominal & pelvic wall, inferior surface of diaphragm
Visceral peritoneum – lines the visceral organs
Both are separated by capillary film of peritoneal fluid
Many organs are suspended by peritoneum folds ( mobile organs )
Retroperitoneal organs are fixed and immobile organs on the posterior abdominal wall
Kidneys, esophagus, pancreas, adrenal glands, aorta, rectum, colon
Folds of peritoneum
I. Greater omentum
- double fold of peritoneum attached to the greater curvature of stomach & covers
the front of the abdomen
- connects the stomach & duodenum to the pancreas
- parts: Gastrocolic ligament, gastrosplenic ligament, gastrophrenic ligament
- function: “policeman of abdomen “ , protect from infection
II. Lesser omentum
- Double fold of peritoneum connecting lesser curvature of stomach and 1 st 2cm of
duodenum to the liver
, - Attachments: superiorly to portal hepatis & inferiorly to the lesser curvature of
stomach and duodenum
- Parts: Hepatogastric ligament & hepatoduodenal ligament
- RIGHT FREE MARGIN OF LESSER OMENTUM – Anterior boundary of epiploic foramen
- Contents: portal vein ( post), hepatic artery ( ant & left ), bile duct ( ant & right )
III. Mesentery proper
- Large, broad, fan-shaped fold of peritoneum attached to coils of jejunum and ileum
- Contents: jejunal & ileal branches of superior mesenteric artery & vein, lymph
nodes, CT
IV. Transverse mesocolon
- Broad fold of peritoneum that suspends the transverse colon from upper part of
post abdominal wall
- Attachment: to the anterior surface of head & anterior border of the body of the
pancreas.
- Contents: Middle colic vessels & lymphatics, trans colon
V. Sigmoid mesocolon
- Triangular fold of peritoneum
- Suspends the sigmoid colon with the pelvic wall
- Contents: Sigmoidal, superior rectal vessels, nerves
VI. Mesoappendix
- Fold of peritoneum around the
appendix, attached to ileocecal junction
- Contents: appendicular artery & vein
