Wk 2 - Anatomy: Biliary Tree, Pancreas and Spleen

Question 1

Where is bile produced?

Answer 1

In the liver by hepatocytes

Question 2

Bile flows along _______ towards _______ of the interlobular portal tract.

Answer 2

Bile flows along bile canaliculi (formed between apposing hepatocytes) towards bile ductules of the interlobular portal tract.

Question 3

Describe the formation of the common bile duct (ie what ducts join together to form it).

Answer 3

1. Bile ductules from the hepatocytes
2. Join to form larger left and right hepatic ducts
3. They merge and exit the porta hepatis as the common hepatic duct
4. And then join with the cystic duct (coming from the gallbladder) to form the common bile duct
5. Which then goes to merge with the main pancreatic duct
6. To then secret the bile into the duodenum (at the major duodenal papilla)

Question 4

Where does the common bile duct secrete into?

Answer 4

Into the duodenum (major duodenal papilla)

Question 5

Where does the accessory pancreatic duct secrete into?

Answer 5

Duodenum at the minor duodenal papilla (MIP)

Question 6

Bile backs up from the closed sphincter of the _____ to get stored and _____ in the _____.

Answer 6

Bile backs up from the closed sphincter of the bile duct to get stored and concentrated in the gall bladder.

Question 7

What are the different parts of the gallbladder?

Answer 7

• Fundus (surface anatomy) = right, 9th costal cartilage, midclavicular line (transpyloric plane)
• Body (relations) = visceral surface of liver, transverse colon, superior part of duodenum

Question 8

List the visceral relations of the gallbladder.

Answer 8

Body (relations) = visceral surface of liver, transverse colon, superior part of duodenum.

Question 9

Describe the position of the bile duct.

Answer 9

• Passes posterior to superior part of duodenum and head of pancreas
• Unites with main pancreatic duct to form hepatopancreatic ampulla, opening into descending duodenum

Question 10

What two ducts join together to form the hepatopancreatic ampulla?

Answer 10

The bile duct unites with main pancreatic duct to form hepatopancreatic ampulla, opening into descending duodenum.

Question 11

What is the purpose of bile?

Answer 11

Bile is used to emulsify fat in the duodenum so it can be absorbed.

Question 12

The gall bladder and most of the biliary tree are lined by cells called ______.

Answer 12

The gall bladder and most of the biliary tree are lined by cells called cholangiocytes.

Question 13

Muscularis externa contracts under ______ stimulation to _____ bile from the gall bladder.

Answer 13

Muscularis externa contracts under CCK stimulation to expel bile from the gall bladder.

Question 14

Why does the gallbladder have microvilli?

Answer 14

Role in water absorption (to concentrate bile)

Question 15

What is the arterial supply of the gallbladder?

Answer 15

Gall bladder, cystic duct and proximal bile duct receive blood via cystic artery, a branch of the hepatic artery proper and the common hepatic artery.

Question 16

What is the cystohepatic triangle?

Answer 16

• Calot’s triangle (cystohepatic triangle) is a small anatomical space in the abdomen.
• It is located at the porta hepatis of the liver – where the hepatic ducts and neurovascular structures enter/exit the liver.

Question 17

What are the borders of the cystohepatic triangle?

Answer 17

• Medial – common hepatic duct.
• Inferior – cystic duct.
• Superior – inferior surface of the liver.

Question 18

What does the pancreas develop from?

Answer 18

Ventral bud (inferior part of head) and dorsal bud (main part of pancreas)

Question 19

What is the pancreas?

Answer 19

• Digestive gland
• Both endocrine and exocrine function
• Exocrine pancreas: produces digestive enzymes (amylase, proteases, lipase…) and bicarbonate ions that are transported via duct system

Question 20

Where is the pancreas located?

Answer 20

• Across the posterior abdominal wall
• At L1 and L2

Question 21

What are the different parts of the pancreas?

Answer 21

Question 22

The pancreas is mostly _____, except for the tail, which is covered in _____.

Answer 22

The pancreas is mostly retroperitoneal, except for the tail, which is covered in peritoneum.

Question 23

What is the exocrine function of the pancreas?

Answer 23

Exocrine pancreas: produces digestive enzymes (amylase, proteases, lipase…) and bicarbonate ions that are transported via duct system

Question 24

Describe the drainage of the pancreatic duct.

Answer 24

Intralobular duct drain to interlobular ducts that drain to pancreatic duct

Question 25

What is the role of the sphincters of the:

• Bile duct
• Pancreatic duct
• Hepatopancreatic ampulla

Answer 25

• Bile duct – controls bile flow
• Pancreatic duct – prevents bile entering pancreas
• Hepatopancreatic ampulla – prevents entry of duodenal contents

Question 26

Why does pain from gallstones radiate to the right shoulder?

Answer 26

Because of the irritation to the diaphragm (close relation to gallbladder) - pain referral to the C3-C5 region (phrenic nerve).

Question 27

What is cholelithiasis?

Answer 27

Cholelithiasis is the presence of one or more calculi (gallstones) in the gallbladder.

Question 28

What is cholecystitis?

Answer 28

Cholecystitis is inflammation of the gallbladder.

Question 29

Gallstones in _______ may cause bile to back up into pancreas leading to ______.

Answer 29

Gallstones in hepatopancreatic ampulla may cause bile to back up into pancreas leading to pancreatitis.

Question 30

What are the two most common causes of pancreatitis?

Answer 30

Alcohol and gallstones

Question 31

Describe the blood supply of the pancreas.

Answer 31

1. Splenic via coeliac
2. Superior pancreaticoduodenal via coeliac
3. Inferior pancreaticoduodenal via SMA

Question 32

What is the lymphatic drainage of the pancreas?

Answer 32

Question 33

What is the spleen?

Answer 33

• Located in the upper left abdomen, and is roughly the size of a clenched fist.
• Lymphatic organ —> In the adult, the spleen functions mainly as a blood filter, removing old red blood cells. It also plays a role in both cell-mediated and humoral immune responses.

Question 34

Where is the spleen located?

Answer 34

• Left handside
• Intraperitoneal
• Well protected by ribs (9th-11th) – in transverse plane
• Posterior to midaxillary line

Question 35

What is the most injured abdominal organ?

Answer 35

The spleen (despite being well-protected)

Question 36

What are the anatomical relations of the spleen?

Answer 36

• Anterior
  
  • Stomach
• Posterior
  
  • Diaphragm
  • Left lung
  • Ribs 9-11
• Superior
  
  • Left colic (splenic) flexure
• Inferior
  
  • Left kidney
  • Tail of the pancreas

Question 37

Describe the peritoneal attachments of the spleen.

Answer 37

The spleen is connected to the stomach and kidney by parts of the greater omentum – a double fold of peritoneum that originates from the stomach:

• Gastrosplenic ligament – anterior to the splenic hilum, connects the spleen to the greater curvature of the stomach.
• Splenorenal ligament – posterior to the splenic hilum, connects the hilum of the spleen to the left kidney. The splenic vessels and tail of the pancreas lie within this ligament.

Question 38

Which layer do the splenic vessels go through to reach the spleen?

Answer 38

The splenic vessels and tail of the pancreas lie within the splenorenal ligament.

Question 39

Describe the vasculature and lymphatic drainage of the spleen.

Answer 39

• Splenic artery
• Splenic vein
• Pancreaticosplenic nodes along splenic artery drain to coeliac nodes

Question 40

Name three causes of splenomegaly (enlargement of the spleen).

Answer 40

1. Increased splenic function (e.g. infection, sickle cell anaemia, removal of erythrocytes)
2. Portal hypertension
3. Leukaemia