Small Intestine Flashcards
(27 cards)
What are the parts of the duodenum?
Superior, descending, horizontal and ascending.
Is the duodenum intraperitoneal or retroperitoneal?
Retroperitoneal.
Is the jejunum intraperitoneal or retroperitoneal?
Intraperitoneal.
Is the ileum intraperitoneal or retroperitoneal?
Intraperitoneal.
Where does the duodenum sit in relation to the pancreas?
The duodenum curves round the head, body and ucinate process of the pancreas.
Is the horizontal part of the duodenum anterior or posterior to the IVC and aorta?
Anterior.
What muscle is found at the duodenojejunal junction and what is its function?
The suspensory muscle of the duodenum. It aids movement of contents into jejunum.
What is the significance of the major duodenal papilla and where is it found?
Found 2/3 of the way down the ascending duodenum.
It marks the transition from the foregut to the midgut and is where the hepato-pancreatic ampulla enters the duodenum.
In what part of the abdomen can the jejunum and ileum be found?
Jejunum - umbilical
Ileum - hypogastrium/pelvis
Compare the jejunum and ileum, commenting on thickness of the wall.
Jejunum thick, ileum thin.
Compare the jejunum and ileum, commenting on size of vasa recta.
Jejunum longer, ileum shorter.
Compare the jejunum and ileum, commenting on number of arcades.
Jejunum less, ileum more.
Compare the jejunum and ileum, commenting on colour.
Jejunum is red, ileum is pink.
What epithelium is found in the small intestine?
Tall columnar absorptive cells - enterocytes.
Name two mucus secreting structures of the small intestine.
Brunner’s glands - alkaline mucus to neutralise stomach acid.
Goblet cells - found throughout mucosa.
The mucosa of the small intestine has many features to increase absorption. Name 3 features.
Plicae Circularis - large circular folds.
Villi - smaller folds on plicae.
Microvilli
What glands can be found between villi?
Crypts of Lieberkuhn.
What cells can be found in the crypts of Lieberkuhn and what are there functions?
Paneth cells - defensive function - contain secretory granules containing lysosomes, defensins and phospholipase.
Stem cells - divide every 2-3 days to replace cells.
Endocrine cells - produce secretin, somatostatin, GLP-1 and serotonin
What is the function of secretin?
Inhibits gastrin, pancreatic acini to secrete H20 and HCO3 when HCl is sensed in the duodenum.
What is the function of somatostatin?
Inhibits gastrin, secretin, CCK, VIP, insulin and glucagon.
What are Peyer’s patches?
Aggregated lymphoid follicles found in the ileum.
What arteries supply the duodenum?
Proximal to the major duodenal papilla - gastroduodenal artery.
Distal to duodenal papilla - inferior pancreaticoduodenal artery (first branch from sup mesenteric).
What artery supplies the jejunum and ileum?
Jejunal and ileal branches of the superior mesenteric artery.
What veins drain the small intestine?
The inferior pancreaticoduodenal veins drain the duodenum (and pancreas).
The jejunal and ileal vein drain the jejunum and ileum.
These veins go into the superior mesenteric vein, which joins with the splenic vein to form the hepatic portal vein.
