Peritoneum and Reflections Flashcards
What is the superior boundary of the abdominal cavity?
Thoracic diaphragm
What is the inferior boundary of the abdominal cavity?
Continuous with pelvic cavity
What are anterior and lateral boundaries of the abdominal cavity?
Abdominal muscles
What is the posterior boundary to the abdominal cavity?
Lumbar vertebrae
Is there a structure separating between the abdominal and pelvic cavity?
No - one big cavity (peritoneum goes into pelvis)
What does the ileum empty into?
1st bit of the colon called the cecum
4 parts of the colon
Ascending, transverse, descending, sigmoid
What does the sigmoid colon join to?
Rectum
Where does the foregut extend to/from?
Oesophagus to middle duodenum
Where does the midgut extend to/from?
Middle duodenum to 2/3rds transverse colon
Where does the handout extend to/from?
2/3rds transverse colon to anus
What does retroperitoneal mean?
Situated outside the peritoneum, in contact with body wall (but intra-abdominally) eg. kidneys (only covered on one side)
Are the kidneys intra or retroperitoneal?
Retroperitoneal (between posterior body wall and peritoneum)
What does intraperitoneal mean?
Suspended from the abdominal wall by a double layered fold of peritoneum. Completely covered by peritoneum on both sides
Are the small intestines intra or retroperitoneal?
Intraperitoneal (suspended in peritoneal sac via mesentery)
What is the mesentery?
- Double layered fold of peritoneum. - Route for nerves, blood vessels, lymphatics.
Where does blood supply to the foregut come from?
Coeliac trunk (single branch of aorta)
Where does blood supply to the midgut come from?
Superior mesenteric artery (branch of aorta)
Where does blood supply to the hindgut come from?
Inferior mesenteric artery (branch of aorta)
During development the whole gut tube has a dorsal mesentery. What does this provide?
- An attachment to the posterior wall
- Separates gut tube from body wall, allowing it to grow longer than body cavity
- Aorta, IVC, spinal cord, sympathetic chain all dorsal
- E.g. important for dorsal with aorta so can get blood vessel to that part of gut tube
What does the mesentery of the small intestine attach it to?
The posterior body wall
How is the transverse colon attached to the posterior wall?
Transverse mesocolon
What separates the peritoneal cavity into supracolic and infracolic compartments?
The mesocolic shelf
What does rotation of the SI during development cause?
- Pushes part of tube against posterior wall
- Loses primitive dorsal mesentery –> not completely invested so is secondarily retroperitoneal (as started intraperitoneal)
What regions of the gut are secondary retroperitoneal?
Ascending and descending colon
What are paracolic gutters?
Grooves either side of tube (important in infection)
Where is the lesser sac of the peritoneal cavity?
Recess of peritoneal cavity behind stomach
What is the greater sac of the peritoneal cavity?
Main peritoneal cavity. This, in turn, is subdivided into supracolic and infracolic compartments.
How are the greater and lesser sacs linked?
Epipoloic foramen
How is the GI tract connected to the posterior wall?
Dorsal mesentery
Where is the ventral msenery (attachment to ventral surface)
Level of the foregut only
Before stomach rotates, what organs develop in dorsal/ventral mesentery?
Ventral –> liver (anterior)
Dorsal –> spleen (posterior)
Due to development of organ in ventral mesentery what happens?
Split into 2 parts:
- Part that goes from gut tube to liver (lesser omentum)
- Part that goes from liver to anterior wall (falciform ligament)
Due to development of organ in dorsal mesentery, what happens?
Split into 2 parts:
- Between spleen and kidney –> Lienorenal ligament (splenorenal ligament)
- Gastrosplenic ligament
How does the stomach rotate?
90 degrees clockwise
As the stomach rotates, what happens?
The liver is pushed to the right hand side
The spleen is pulled around to the left hand side
Lesser sac pulled behind stomach
Greater sac pulled anterior to stomach
What happens to the dorsal mesentery in order for this rotation to occur?
Increases in size so rapidly it folds back on itself to attach to posterior wall
Mesentery hanging from stomach:
Attaches to dorsal aspect –> greater omentum
Attaches to liver from ventral mesentery –> less omentum
Where is the lesser omentum?
Between lesser curvature of stomach to liver
Where is the falciform ligament?
From liver to anterior wall
Where do the lesser omentum and falciform ligament arise from?
Ventral mesentery
Where does greater omentum arise from?
From dorsal mesentery, folds back on itself and attaches to posterior wall
How can infection spread around the abdomen?
Epiploic foramen
What can the greater sac be subdivided into?
The supracolic and infracolic compartments. These are both within the greater sac but located above and below the transverse colon when pulled anteriorly.
What are the features of the infracolic compartment?
- Paracolic gutters
- The mesentery
