Peritoneum Flashcards
What are the X3 primitive subdivisions of the alimentary tract?
What do each of these equate to in the fully developed alimentary tract?
Foregut = tract up to the proximal duodenum
Midgut = proximal duodenum —> 2/3 along the transverse colon
Hindgut = final 1/3 transverse colon —> rectum
What is the blood supply to the foregut structures?
Where does this vessel arise from?
Via the celiac trunk, a branch of the abdominal aorta at the level of T12.
What is the blood supply to the midgut structures?
Where does this vessel arise from?
Via the superior mesenteric artery, a branch of the abdominal aorta at the level of L1.
What is the blood supply to the hindgut structures?
Where does this vessel arise from?
Via the inferior mesenteric artery, a branch of the abdominal aorta at the level of L3.
What term is used to describe organs with a mesentary?
And those without a mesentary?
Intra-peritoneal.
Retro-peritoneal.
What is the difference between primary and secondary retro-peritoneal organs?
Primary = developed without a mesentary
Secondary = developed with a mesentary which was reabsorbed into the parietal peritoneum
In development, what caused organs such as the pancreas and duodenum to become retro-peritoneal?
The enlarging liver, forcing them backwards to become retro-peritoneal.
In development, how were the visceral peritoneum and the mesenteries formed?
The peritoneum from each side of the body merged in the midline to form the visceral peritoneum and the mesenteries.
Which organs are found in the peritoneal cavity?
None! All organs are intra or retro-peritoneal.
What is the name of the central mesentary initially formed in development, which suspends the stomach?
The mesogastrium.
What is the name of the mesogastrium found “in front” of the stomach during development?
The anterior/ventral mesogastrium.
What is the name of the mesogastrium found “behind” of the stomach during development?
The posterior/dorsal mesogastrium.
What do the mesogastrium eventually turn into as development continues?
Ligaments.
The growth of what occurs in this midline of mesogastrium (ventral & dorsal)?
The upper abdominal organs:
- Kidneys
- Spleen
- Liver
- pancreas
What ligament connects the liver to the stomach?
The gastrohepatic ligament, also known as the LESSER OMENTUM.
What ligaments connects the stomach to the spleen?
The gastrosplenic ligament.
What ligament connects the spleen to the kidneys?
The splenorenal ligaments.
How does the stomach move as it is forming?
It rotates anti-clockwise and moves upwards, also growing faster on one side to creates a greater and lesser curvature.
What does the rotation of the stomach do to its dorsal mesogastrium and what X2 structures does this form?
The anti-clockwise stomach rotation pulse the dorsal mesogastrium to the left side of the body, creating a peritoneal subdivision called the OMENTAL BURSA (lesser sac).
The dorsal mesogastrium continues to grow caudally to form the GREATER OMENTUM.
How many layers is the greater omentum formed of?
X4 layers, but the inner two fuse.
What is the role of the greater omentum?
It plays a part it localising infection, sticking to it and aiding the delivery of lymphocytes via omental arteries (branches of the gastroepiploic arteries which follow the greater curvature of the stomach).
What travels in the ligaments?
Blood vessels/lymphatics.
What is the lesser sac?
How can it be accessed?
It is the space behind the stomach, accessed underneath the lesser omentum via the EPIPLOIC FORAMEN.
Which parts of the small intestine are intra-peritoneal?
Which mesentery is this?
The jejunum and ileum.
THE mesentery!
Which parts of the large intestine are intra-peritoneal?
What are their respective mesenteries called?
The transverse colon and sigmoid colon.
They are called MESOCOLONS (transverse mesocolon & sigmoid mesocolon).
What is the greater sac split into by the transverse mesocolon?
What spaces link these two together?
It splits the greater sac into supra- and infra-colic complements.
These are linked by PARACOLIC GUTTERS.
How many pelvic peritoneal folds do males have?
What are they called?
X1 = rectovescicle pouch.
“Vesico” prefix = bladder
How many pelvic peritoneal folds do females have?
What are they called?
X2:
= vesicouterine pouch
= rectouterine pouch
(“Vesico” prefix = bladder)
What ligament connects the liver to the anterior abdominal wall?
The falciform ligament.
