The small intestines - jejunum and ileum Flashcards
where is the jejunum and ileum located?
distal 2 parts of small intestines
where does the jejunum and ileum lie?
intraperitoneal (within the peritoneal cavity)
what is the jejunum and ileum attached to? by what?
attached to the posterior abdominal wall by mesentery (a double layer of peritoneum)
where does the jejunum begin?
duodenojejunal flexure
is there a clear distinction between the jejunum and ileum?
There is no clear external demarcation between them jejunum and ileum, although the two parts do have some differences
where does the ileum end?
ileocecal junction
what happens at the ileocecal junction?
the ileum invaginates into the cecum to form the ileocecal valve
what is the function of the ileocecal valve?
it prevent reflux of material back into the ileum
can the ileocecal valve control movement of material from ileum to the cecum?
Although it is not developed enough to control movement of material from the ileum to the cecum
where is the jejunum located?
upper left quadrant
what is a characteristic feature of the jejunum wall?
thick intestinal wall
what colour is the jejunum?
red
what are characteristic features of the jejunum?
- longer vasa recta (straight arteries)
2. less arcades (arterial loops)
where is the ileum located?
mainly in the lower right quadrant
what is a characteristic feature of the ileum wall?
thin intestinal wall
what colour is the ileum?
pink
what are characteristic features of the ileum?
- shorter vasa recta (straight arteries)
2. more arcades (arterial loops)
what are the sources of arterial supply to the initial part of duodenum?
gastroduodenal artery
what is the gastroduodenal artery a branch of?
celiac trunk
what is the arterial supply to the distal to the major duodenal papilla?
inferior pancreaticodudenal artery
what is the inferior pancreaticodudenal artery a branch of?
superior mesenteric artery
why is the transition form the initial to the distal to major duodenum important?
it parts the change from the embryological foregut to midgut
where do the veins of the duodenum travel? and where does it drain into?
The veins of the duodenum follow the major arteries and drain into the hepatic portal vein
where does the arterial supply to the jejunoileum (jejunum and ileum) come from?
superior mesenteric artery
where does the superior mesenteric artery arise from? where is it located?
from the aorta at the level of the L1 vertebrae, immediately inferior to the celiac trunk
where does the superior mesenteric artery travel? what happens as it travels?
It moves in between layers of mesentery, splitting into approximately 20 branches
what happens to the branches of the superior mesenteric artery?
These branches anastomose to form loops, called arcades
what happens to the arcades?
From the arcades, long and straight arteries arise, called vasa recta
which vein drains the jejunoileum?
The venous drainage is performed by the superior mesenteric vein.
which vein drains the jejunoileum?
The venous drainage is performed by the superior mesenteric vein
what does the superior mesenteric vein join with? where does it join and what does it become?
It unites with the splenic vein at the neck of the pancreas to form the hepatic portal vein
