What is the peritoneum?
Continuous membrane lining the abdominal cavity consisting of mesothelial layer supported by a layer of connective tissue
What is the abdominal wall?
Muscle and connective tissue deep into which lies the abdominal cavity
What is the peritoneum made of?
Single continuous membrane of simple SQUAMOUS epithelium (mesothelium)
What is the peritoneal cavity?
Potential space within the layer of peritoneum
What is present in the abdomino-pelvic cavity?
Abdomen: Small intestine, asc/desc colon, cecum and appendix Pelvic: Sigmoid colon, rectum Thoracic cage: liver, gall bladder, transverse colon, stomach, spleen
Where does the gut tube originate from?
Endoderm and splanchnic mesoderm - 4 weeks IUL
From where is the gut tube suspended?
From the posterior abdominal wall by the dorsal mesentery
What are mesenteries?
Peritoneal folds attaching viscera to abdominal wall
What are the functions of mesenteries?
Conduit for VESSELS, NERVES and LYMPHATICS supplying viscera.
What is the difference between visceral and parietal peritoneum?
Visceral peritoneum surrounding the viscera Parietal peritoneum lines the abdominal cavity.
What is the difference between intra and retroperitoneal?
INTRAperitoneal – structures, like most of small intestine, suspended from the abdominal wall by mesenteries. RETROperitoneal – structures, like kidneys and great vessels that lie between parietal peritoneum and abdominal wall.
What are some retroperitoneal organs on posterior abdominal wall?
Kidneys & ureters Suprarenal glands Aorta/Inferior vena cava Nerves: lumbar plexus, sympathetic trunk Oesophagus Rectum
What are some secondarily retroperitoneal organs and what does this mean?
They had a mesentery but it fused with the abdominal wall: Duodenum (except the first part) Pancreas (tail is INTRAperitoneal) Colon (ascending and descending only)
What are the 3 divisions of the GIT?
FOREGUT – Distal 3rd of oesophagus to the 2nd part of the duodenum at the entrance of the bile duct (Major duodenal papilla). MIDGUT – 2nd part of the duodenum to two-thirds along transverse colon. HINDGUT – Distal third of transverse colon to the rectum.
Why is it important to divide the GIT into 3 parts?
Each part of GIT has its own arterial supply, coeliac trunk, superior mesenteric artery
What does the dorsal mesentery do?
Suspend the entire gut
What is special about the foregut?
It is suspended by both dorsal and ventral mesentery
What is in the ventral mesentery?
Foregut, liver - split into falciform ligament and lesser omentum
How is the omental bursa (lesser sac) of the peritoneal cavity formed?
As the liver grows, it moves to the right, while the dorsal mesentery and spleen move to the left, so original right side of upper peritoneal cavity is now posterior
What does the omental bursa look like?
How are the greater and lesser omentum formed?
Lower part of dorsal foregut mesentery extends down as a double fold called greater omentum (apron) anterior to intestine Lesser omentum is part of ventral foregut mesentery
What is the epiploic foramen?
Entrance to lesser sac
What do the greater and lesser omentum look like?
Where do the portal vein, hepatic artery and bile duct run through?
Between the posterior abdominal wall and liver within lesser omentum near its free edge
Why is there a free edge present in the lesser omentum?
Due to ventral mesentery ending at start of midgut
What do the greater and lesser sacs look in sagittal view?
What are the names of the peritoneal compartments?
Supracolic compartment, mesentery of transverse colon, infracolic compartment (R/L), R/L paracolic gutter, mesentery of small intestine
Fill in the peritoneal compartments in this picture:
How does the peritoneal fluid flow in peritoneal cavity?
How does the inflammatory exudate flow in the peritoneal cavity?