S5 L1 Pancreas and Liver

Question 1

When chyme enters the duodenum from the stomach, describe the properties of the chyme
- 3 properties and why

Answer 1

Hypertonic because:
- food produces lots of solutes that are dissolved in gastric juice
◦ Stomach wall is largely impermeable to water, Water cannot dilute solute in chyme, Tonicity
- More digestion = more osmotically active molecules
- Osmotically active chyme developing within the stomach - cant move water into stomach lumen due to wall impermeability

Question 2

What mechanisms solve these 3 ‘problems’

Answer 2

Question 3

Why must chyme release by controlled?

Answer 3

Question 4

Pancreatic secretions:
- What are the 2 main types of the secretions of the pancrease
- More info into structure of these types of cells (ones that are to do with food)
3 main sections
- Pancreas is innervated by what 2 nerves?

Answer 4

Question 5

Recap and a bit more info:

• The acinus is stimulated by what 2 things…
• Which enzymes does the pancreas secrete?
• What ‘state’ are these enzymes in and why?

Answer 5

Question 6

Pancreatic secretions:

• How are the enzymes formed and releaesed?
• At higher flow rates - how does this affect secretions?

Answer 6

At higher flow rates
◦ Increased secretion of HCO3 (for acid neutralisation)
◦ Increased HCO3 in pancreatic secretion

Question 7

Zymogen granules

• What are these?
• Why do they exist?
• Contain what?
• Example
• How to detect pancreatitis?

Answer 7

Question 8

Liver:
- Involved in… roles

Answer 8

Question 9

Hepatocytes:

• What are these cells?
• Make up what mass of the liver?
• Describe the structure of the hepatic lobule (3 main vessels/tube), where do they flow to?
• Dual blood supply, by what…

Answer 9

Question 10

What is a liver lobule?

• Drainage of central vein into…. where?
• What is a portal triad

Answer 10

Question 11

What is an acinus

• Zones…
• Zone 1 most at risk from…
• Zone 3 most at risk from…

Answer 11

Question 12

Other bits:

• Blood from where drains into the liver?
• Does the liver get any oxygenation from portal vein?
• How does bile drain (and from where to where)?

Structure of liver cont/recap:

• Blood flowing into liver by…
• Bile flows out…

Answer 12

Blood flowing in:
◦ Venous portal blood
◦ Arterial blood (hepatic arteries)
– Flowing toward central vein
–Which then drains into hepatic veins (vena cava)

Bile flowing out:
◦ Along canaliculi
◦ Bile ducts to Duodenum

Question 13

Bile and bile acids:

• 2 components name and describe what molecules these includes…, secreted by what…,
• what are the 2 primary bile acids?
• what are bile salts and give examples

Answer 13

2 primary bile acids
◦ Cholic acid
◦ Chenodeoxycholic acid
– Further bile acids formed in gut

Bile salts are bile acids that are conjugated with the amino acids
◦ Glycine
◦ Taurine

Bile salts = bile acids + aa’s

Question 14

Why release bile salts and not just release bile acids?
- 2 reasons

Answer 14

Question 15

Digestion of fats
- 2 main roles of bile salts

Answer 15

Question 16

Digestion of fats:
- Steps of getting fats in micelles into the blood stream

Answer 16

Question 17

How is bile recycled?

Answer 17

Question 18

Gallbladder:

• Role
• What does it do to the bile?
• What is the risk of this?
• What stimulates gallbladder contraction?
• How does the bile fill the gall bladder?

Answer 18

Question 19

Steatorrhoae and Bile pigment

• What is steotorrhoea?
• Signs of it?
• What is bilirubin?
• What happens to bilirubin?
• What can this lead to if it builds up?

Answer 19