Session 2 - the Gut and the Peritoneal Cavity Flashcards
What is the peritoneum?
the serous membrane lining the cavity of the abdomen and covering the abdominal organs (the peritoneal/abdominal cavity)
What is the mesothelium?
the epithelium that lines the pleurae, peritoneum, and pericardium
What is the difference between the abdominal and peritoneal cavities?
abdominal cavity is between the abdominal wall and the peritoneum (there is nothing here)
the peritoneal cavity is within the layers of the peritoneum
What are mesenteries?
periteoneal folds that attach viscera to the abdominal wall
they are conduits for vessels, nerves and lymphatics supplying viscera
Normally, there are only 2 germ layers during embryological development. In the development of the gut tube, there are 3, what are they?
ectoderm
mesoderm
endoderm
After the endoderm and ectoderm have formed, interactions between the two germ layers induce the development of mesoderm. The mesoderm forms skeletal muscle, bone, connective tissue, the heart, and the urogenital system
The gut tube is suspended from the posterior abdominal wall by a peritoneal fold. Name it
the dorsal mesentery
What are the visceral and parietal peritoneum?
visceral - covers the suspended organs
parietal - lines the abdominal wall
What does intraperitoneal and retroperitoneal refer to?
intraperitoneal - structures suspended from the abdominal wall by mesenteries. They are enclosed completely by the peritoneum
retroperitoneal - structures that lie between the parietal peritoneum and the abdominal wall
Give an example of intraperitoneal and retroperitoneal structures
intra - most of the small intestine
retro - kidneys and great vessels
How do organs become secondarily peritoneal?
organs originally had a mesentery, it fuses with the body wall
Which mesenteries are there in the gut?
dorsal
the forgut has a ventral mesentery
NO VENTRAL MESENTERY OF THE GUT
What is the omental bursa/lesser sac?
a hollow space that is formed by the greater and lesser omentum and its adjacent organs.
It communicates with the greater sac via the epiploic foramen of winslow, which is known as the general cavity of the abdomen that sits within the peritoneum, but outside the lesser sac.
What is different about the muscle layers of the stomach compared ofthe rest of the GI tract?
it has 3 layers, and the rest of the GI tract has 2
What is the pyloric sphincter and what is its role?
a ring of smooth muscle of the distal end of the pyloric canal that prevents food from entering the duodenum
What is located at the first part of the duodenum?
duodenal cap (common location for duodenal ulcers)
What is located at the second part of the duodenum?
the major duodenal papilla - entrance for the common bile duct
What type of peritoneal structure is the duodenum?
retroperitoneal
What does hepatic refer to?
the liver
What are portal systemic anastomoses?
where veins draining the portal vein and the IVC communicate
Describe the lymphatic drainage
- it follows the arterial supply
- all lymph drains into the cisterna chyli and then the thoracic duct
What does the omental foramen connect?
the lesser and greater sac
How is the greater sac divided into compartments?
can be divided by the dorsal mesentry at the transverse colon into two compartments
- Supracolic
- Infracolic
This is further subdivided by the dorsal mesentry of the small intestine into
- Right infracolic
- Left infracolic
