Lecture 10- Intestines

Question 1

Duodenum, jejunum and ileum

Answer 1

Site of digestion and absorption

Question 2

junction between jejunum and ileum

Answer 2

• No specific junction between the 2
  
  • However jejunum is wider and has more folds (greater surface area than distal jejunal-ileum) and tapers to become the ileum

Question 3

features of the jejunum

Answer 3

• Located in upper left quadrant
• Thick intestinal wall
• Longer vasa recta (straight arteries)
• Less arcades (arterial loops)

Question 4

features of the Ileum

Answer 4

• Located in lower right quadrant (sits fairly centrally)
• Thin intestinal wall
• Shorter vasa recta
• More arcades

Question 5

permanent folds of the jejunum are called

Answer 5

plica ciruclares

• Go all the way across the lumen- helps distinguish small and large bowel on imagining
• Can see the villi (not microvilli- too small) on the plica circulares

Question 6

the mesentry attaches to

Answer 6

a20ft of small bowel

Question 7

function of the mesentry

Answer 7

helps pack in the small bowel and stops it from twisting

Question 8

• Mesentery

Answer 8

is a double fold of peritoneum (visceral) that envelops the small bowel

Question 9

• Between the two layers of the peritoneum (that forms the mesentry) WHAT IS FOUND

Answer 9

• Layers of fat
• Blood vessels
• Lymphatics
• Acts as a conduit for artery’s, veins and lymphatics without having to enter the peritoneal cavity

Question 10

vessels of the mesentry are arranged in

Answer 10

arcades and straight blood vessles

Question 11

root of the mesentry

Answer 11

from the patients top left to bottom right quadrant (25cm long)

• Starts where the jejunum starts
• Ends at the terminal ileum
• Attached to the posterior peritoneal cavity

Question 12

where does B12 absorption happen

Answer 12

distal ilum

Question 13

distal ileum is also a

Answer 13

common site for IBD

Question 14

Blood supply of the midgut structures

Answer 14

- superior mesenteric artery

• SMA- artery of the midgut
• Out from under the pancreas
• Goes over the uncinate process
• From the superior mesenteric artery we get (think of this moving in clockwise direction)
  
  • Jejunal and ileal arteries- coming off top the left
  • Ileocolic artery – terminal ileum and colic part of the colon
  • Right colic artery
  • Middle colic artery

Question 15

Venous drainage of the midgut

Answer 15

• Superior mesenteric vein
• Joins up with many different veins to form the hepatic portal vein
• Supplies the liver with lots of blood (80% of blood going to the liver)

Question 16

summary of blood supply and venous drainage of the gut

Answer 16