Week 5-Midgut and Hindgut Flashcards
Where does the midgut extend from?
1/2 along the duodenum, jejunum, ileum, caecum, appendix, ascending colon to 2/3rd along the transverse colon.
What is the main arterial blood supply to the midgut?
Branches of the superior mesenteric artery.
what level does the superior mesenteric artery branch off the aorta?
L1.
Where does the hindgut extend from?
Starts 2/3rds of the way along the transverse colon, descending colon, sigmoid colon, rectum and anal canal.
What is the main arterial blood supply to the hindgut?
Branches from inferior mesenteric artery.
What attaches to both the jejunum and ileum to attach them to posterior abdominal wall?
Mesentery
Where does the jejunum start?
At the duodenal-jejunal junction.
Where does the ileum end?
Ileocaecal junction
Which part of the small intestine is biggest?
The ileum- 3/5ths
Jejunum- 2/5ths
Duodenum-20cm
Approximately how long is the small intestine?
6m long.
What are the grooves in the wall of the small intestine called?
Plicae circularis.
Compare the walls of the jejunum and ileum
Jejunum has more plicae circularis and its thicker than the ileum.
Which has the wider lumen (bore) out of the jejunum and ileum?
Jejunum has a wider bore (lumen) than the ileum.
What is an arcade?
An arcade is an area where arterial branches anastomose before reaching their final destination.
Compare the arcade structure of the jejunum vs the ileum
The jejunum has fewer arcades with long branches to the wall.
The ileum has loads of arcades and numerous short branches to the ileum wall.
Where would you find adipose tissue in the jejunum and ileum?
In the jejunum it is mostly found around the root of the mesenteric vessels whereas in the ileum its throughout the mesentery.
Compare the lymphoid tissue in the ileum and the jejunum?
Ileum- numerous Peyers patches
Jejunum- few small lymphoid tissues.
Which branches of the superior mesenteric artery supply the ileum and jejunum?
The jejunal and ileal branches of the superior mesenteric artery. The lower parts of the ileum are supplied by the ileocolic artery.
Where do the veins from the ileum and jejunum drain into?
They drain into the superior mesenteric vein.
Where does lymph from the ileum and jejunum drain to?
Drains to mesenteric nodes and then to the pre-aortic nodes at L1 around the superior mesenteric artery.
Where do the autonomic nerves to the midgut come from?
From the superior mesenteric plexus.
Where would pain from the midgut be felt?
Umbilical region.