Peritoneum Flashcards
what is the peritoneal membrane?
a serous membrane that lines the abdominal cavity, forming the peritoneal cavity
What are the paired muscles that form the anterolateral abdominal wall?
- external oblique
- internal oblique
- transversus abdominis
How are the muscles of the anterolateral abdominal wall supported?
They are supported anteriorly and posteriorly by”
- rectus abdominis
- quadratus lumborum
What are the superior and inferior borders of the abdominal cavity?
The superior limit of the abdominal cavity is the thoracic diaphragm
Inferiorly, the abdominal cavity is continuous with the pelvic cavity
What are the anterior, lateral and posterior limits of the abdominal cavity?
Anteriorly and laterally, the abdominal cavity is defined by the abdominal muscles
The posterior limit of the abdominal cavity are the lumbar vertebrae
What are the limits of the foregut?
The foregut runs from the oesophagus to middle duodenum
what are the limits of the midgut?
The midgut runs from middle duodenum to 2/3 of the way along the transverse colon
What are the limits of the hindgut?
The hindgut runs from 2/3 of the way along the transverse colon to the anus
What is significant about the divisions of the GI tract?
Each section of the GI tract has its own venous drainage, arterial supply and nerve plexus
What is the parietal peritoneum?
The layer of peritoneum lining the abdominal wall, pelvic wall and inferior surface of the diaphragm
What is the visceral peritoneum?
The layer of peritoneum that specifically covers a viscus (organ)
How are the visceral and parietal peritoneum related?
The parietal and visceral layers of peritoneum are continuous
What is meant by retroperitoneal?
When a structure is situated outside of the peritoneum, but is in contact with the body wall intra-abdominally
Why are the kidneys described as being retroperitoneal?
They are situated between the posterior body wall and the peritoneum
What is meant by intraperitoneal?
When a structure is suspended from the abdominal wall by a double-layered fold of peritoneum (mesentery)
What is meant by a mesentery?
a double-layered fold of peritoneum which acts as a route for nerves, blood vessels and lymphatics
In general, what types of structures tend to be intraperitoneal?
Structures that change size and shape
During development, what type of mesentery is present?
What does it do?
Dorsal mesentery
It separates the gut tube from the body wall
This allows the gut tube to grow longer than the body cavity
Why is the dorsal mesentery called “dorsal”?
As the aorta, inferior vena cava, spinal cord and sympathetic chain are all dorsal structures
In the adult, which parts of the small intestine retain a mesentery?
The jejunum and the ileum
This is the mesentery of the small intestine
In the adult, which part of the colon retains a mesentery?
The transverse colon
This is the transverse mesocolon which runs horizontally across the posterior abdominal wall
What is the role of the mesocolic shelf?
This is formed from the transverse mesocolon
It separates the peritoneal cavity into supracolic and infracolic compartments
Which parts of the colon become secondarily retroperitoneal in the adult?
The ascending and descending colon
What is a secondarily retroperitoneal organ?
Organs which were once suspended within the abdominal cavity by a mesentery
During the course of embryogenesis, they became retroperitoneal
What is a primarily retroperitoneal organ?
An organ which has been retroperitoneal throughout the entirety of development
What are paracolic gutters?
Spaces between the colon and the abdominal wall
What is the main peritoneal cavity and how is it divided?
The greater sac
It is divided into the supracolic and infracolic compartments
What is the lesser sac?
It is a recess of the peritoneal cavity between the stomach and the posterior abdominal wall
How are the greater and lesser sacs linked?
Through the epiploic foramen
During development, what structures are suspended by the dorsal mesentery?
The dorsal mesentery extends for the whole length of the developing gut tube
The foregut, midgut and hindgut are connected to the posterior abdominal wall by the dorsal mesentery
Which part of the GI tract during development has both dorsal and ventral mesenteries?
Only the developing foregut has both dorsal and ventral mesenteries
The ventral mesentery has a free lower border midway along the duodenum
Whereabouts do the liver and spleen begin to develop?
The liver develops in the ventral mesentery
The spleen develops in the dorsal mesentery
What is the lienorenal ligament and what is it derived from?
It runs between the left kidney and the spleen
It is derived from the peritoneum, where the wall of the greater sac comes into contact with the omental bursa (lesser sac)
What passes between the two layers of the lienorenal ligament?
The lineal vessels
These are the splenic artery and vein
What is the gastrosplenic ligament and what is it derived from?
It is peritoneum that connects the greater curvature of the stomach with the hilum of the spleen
It is part of the greater omentum
What is the role of the falciform ligament?
It attaches the liver to the anterior abdominal wall
What happens to the dorsal mesentery during rotation of the stomach?
The dorsal mesentery ‘balloons’ to the left to form the greater omentum
What is the greater omentum?
A large fold of visceral peritoneum that hangs down from the stomach
It connects the stomach to the posterior abdominal wall
