Anatomy - Biliary tree, small intestine and pancreas

Question 1

Describe jaundice (icterus)

What causes it?

Answer 1

A buildup of bilirubin in the blood

Question 2

Describe the normal journey of bilirubin

Answer 2

RBCs broken down in the spleen
–>
Bilirubin goes to the liver where it is incorporated into bile
–>
Bile is secreted into the 2nd part of the duodenum

Question 3

Describe the biliary tree

Answer 3

Right and left hepatic ducts fuse to form the common hepatic duct

The cystic duct (from the gallbladder) fuses with the common hepatic duct to form the common bile duct

Merges with the main pancreatic duct

Makes the ampulla of Vater

Drains into the 2nd part of the duodenum

Question 4

Describe the ampulla of Vater

Answer 4

The biliary tree and main pancreatic duct merge to form the ampulla of Vater

this is a wider section that feeds into the 2nd section of the duodenum via the sphincter of Oddi and the major duodenal papilla

Question 5

Describe the sphincters of the biliary tree

Composition?
Names?
Locations?
Functions?

Answer 5

circumferential smooth muscle sphincters

There are 3:

• bile duct sphincter
• pancreatic duct sphincter
• sphincter of Oddi

Function:
Bile duct sphincter:
- controls the flow of bile

Pancreatic duct sphincter:
- controls the flow out of the main pancreatic duct

Sphincter of Oddi:
- Prevents duodenal chyme and juice entering the biliary tree

Question 6

Describe an endoscopic retrograde chalangiopancreatography

Answer 6

Endoscope is inserted orally, and goes to the duodenum

Secretes dye up the biliary tree

Radiography is then used to image and treat the biliary tree

(CAN be used directly for treatment)

Question 7

Describe post-hepatic jaundice

Answer 7

Jaundice that is caused by a biliary tree obstruction

gallstones/pancreatic enlargement
-->
biliary tree obstructed
-->
back pressure up the tree
-->
bile is stuck in the liver
-->
bile (and bilirubin) spills into the blood

Question 8

Describe the pancreas

• anatomical relationships
• relationship with the peritoneum
• parts

Answer 8

5 parts:

• Head (in the “C” of the duodenum)
• Uncinate process
• Neck
• Body
• Tail

It is retroperitoneal, lies against the posterior abdominal wall

stomach = anterior
splenic vessels = superoposteriorly

posterior = right kidney, IVC, aorta, bile ducts, sup. mesenteric vessels

Question 9

Describe the function of the pancreas

Answer 9

Exocrine:
- produces digestive enzymes into the duodenum, via the main pancreatic duct

Endocrine:
- makes insulin and glucagon

Question 10

Describe the control of the pancreas

Answer 10

Hormonal:

• Majority of control
• by hormones from the duodenum

Innervation:
symp = abdominal splanchnic
para = vagus

They from the celiac and sup. mesenteric plexuses, and then go perivascularly

Question 11

Which arteries supply the pancreas?

Answer 11

Pancreatic arteries (from the splenic)

Sup. pancreaticoduodenal artery

Inf. pancreaticoduodenal artery

Question 12

Describe pancreatic pain

Cause?
Location?
Referred pain?

Answer 12

Often due to pancreatitis

Caused by:
Ampulla of Vater getting blocked by a gallstone
–>
Bile goes into main pancreatic duct and pancreas

Pain:
- epigastric/umbilical region

Referred pain:
- midline back, between shoulder blades

Question 13

Name the 3 parts of the small intestine

Which parts are foregut and which are midgut?

Answer 13

duodenum
-->
jejunum
-->
ileum

Foregut:
- first 2 parts of the duodenum

Midgut:
- everything else

Question 14

List the 4 parts of the duodenum

Describe their relationship to the peritineum

Answer 14

1- superior (duodenal cap)
2- descending
3- horizontal
4- ascending

Intraperitoneal:
- duodenal cap

Retroperitoneal:
- descending, horizontal, and ascending

Question 15

What marks the start and end of the duodenum?

Answer 15

starts = pyloric sphincter

end = duodenal-jejunal flexure

Question 16

Describe the blood supply of the duodenum

Answer 16

Sup. pancreaticoduodenal artery

Inf. pancreaticoduodenal artery

Question 17

Describe the locations of the duodenum, jejunum, and ileum in the abdomen using the quadrant system

Answer 17

Duodenum:
- left and right upper quadrants

Jejunum:

• Left (and right) upper quadrants
• left lower (a bit)

Ileum:

• right and left lower quadrants
• right upper (a bit)

Question 18

What marks the end of the ileum?

Answer 18

ileocaecal junction

Question 19

Describe the differences in the walls of the jejunum and ileum

Answer 19

Wall width:
- Wall thickness decreases down the tract

Plicae circulares:

• folds become less down the tract
• (ileum is smoother)

Lumen width:
- Decreases down the tract

Question 20

Describe the blood supply of the jejunum and ileum

Answer 20

sup. mesenteric artery
–>
jejunal and ileal arteries

(Vessels travel in the mesentery)

Question 21

Describe the venous drainage of the jejunum and ileum

Answer 21

jejunal and ileal veins
-->
sup. mesenteric vein
-->
hepatic portal vein

Question 22

Describe fat absorbtion

Answer 22

Chylomicrons in lumen
-->
lacteal
-->
lymphatics
-->
left venous angle

Question 23

Describe the lymph nodes of the abdomen

Answer 23

Most surround the arterial trunk

• Celiac
• sup. mesenteric
• inf. mesenteric
• lumber