Pancreas and Liver

Question 1

What is the exocrine pancreas and liver?

Answer 1

Accessory organ for intestines

Question 2

What is the function of the exocrine pancreas and liver?

Answer 2

Provides excretions directly into intestine lumen to digest, lipids and proteins in the small intestine

Question 3

What is the endocrine function of the pancreas and liver?

Answer 3

Regulate blood borne energy substrate availability by hormones. Eg. glucose, fatty acids, ketones

Question 4

Properties of the pancreas?

Answer 4

Has both exocrine and endocrine functions
The pancreatic duct located on the 2nd part of the duodenum secretes pro-enzymes
Behind peritoneum
Close to major blood vessels making it difficult to access

Question 5

Different regions of pancreas

Answer 5

head
neck
body
tail
uncinate

Question 6

What components does the main pancreatic duct work in conjunction with?

Answer 6

Bile duct and the 3 components of the sphincter of Oddi

Question 7

What supplies the pancreas?

Answer 7

The splenic artery and the pancreatico-duodenal arteries from the coeliac trunk

Question 8

What are the primary functions of the exocrine pancreas?

Answer 8

Neutralise acid

Deliver enzymes for macronutrient digestion in duodenum

Question 9

Properties of acinar cells

Answer 9

Main secretory cells

Clusters connected with intercalated ducts that converge on the collecting duct

Question 10

What is the role of lining cells?

Answer 10

Add ions and secretions to acinar cells

Question 11

Dependencies of pancreas regulation?

Answer 11

cephalic phase of digestion: vagus nerve stimulates pancreatic secretions by releasing ACh and VIP
gastric phase of digestion: regulated by vagovagal reflexes
intestinal phase of digestion: controlled by hormone secretin and CCK

Question 12

What are the different enzyme secretion mechanisms in the pancreas?

Answer 12

zymogen granules on acinar cells
released in response to CCK
activation causing zymogen granules to exocytose from acinar cells into luminal space

Question 13

What do zymogen granules do?

Answer 13

House inactive and active digestive enzymes

Question 14

Explain how CCK regulates exocytosis of zymogen

Answer 14

Hormonally and neurally
CCK released into interstitial space, enters bloodstream, circulates to pancreatic acinar cells and binds to CCKA receptors
CCK can also bind to CCKA receptors on vagal afferents giving efferent stimulation of pancreatic acinar cells via VIP

Question 15

Explain ion secretion in acinar cells

Answer 15

Basolateral CCK and ACh binding stimulates Cl- transport across apical membrane. This facilitates paracellular movement of water and Na+

Question 16

Explain ion secretion in intercalated duct cells

Answer 16

ACh and secretin bind which activates cystic fibrosis transmembrane conductance regulators, Cl- channels and Cl-HCO3 co-transporters which recycle Cl- and HCO3

Question 17

What happens with increased flow rate of ion secretion?

Answer 17

HCO3 increases
Cl- decreases
K+ and Na+ are unaffected

Question 18

Where can the liver be palpable?

Answer 18

Below costal margin

Question 19

What is Glisson’s capsule and where is it found?

Answer 19

It is a thin connective tissue layer with extensions into the organ between the lobules completely surrounding the liver

Question 20

What supplies the liver?

Answer 20

The hepatic portal vein which brings absorbed nutrients from the gut and stomach
the hepatic artery which supplies hepatocytes with oxygen

Question 21

How is bile drained from the liver?

Answer 21

Drained by canaliculi found between hepatocytes into bile ductules and eventually into bile ducts

Question 22

Explain venous drainage of the liver?

Answer 22

Hepatic veins that enter the inferior vena cava

Question 23

What separates the right and left lobes of the liver?

Answer 23

The falciform ligament

Question 24

Different lobes of the liver?

Answer 24

Right, left and a quadrate lobe

Question 25

What is the bare area of the liver?

Answer 25

The diaphragmatic surface with no peritoneal covering

Question 26

What are the functions of the liver?

Answer 26

Synthesis and secretion of bile
Storage
Detoxification
Synthesis of blood clotting and anti-coagulation factors

Question 27

What components are in bile?

Answer 27

Bile pigments, mainly bilirubin
Cholesterol
Phospholipids
Fatty acids
Water
Electrolytes

Question 28

What are bile pigments derived from?

Answer 28

Breakdown of products of haemoglobin

Question 29

What are Kupffer cells and what do they do?

Answer 29

They are fixed phagocytes which plays a role in the formation of bile pigments

Question 30

What do bile salts do?

Answer 30

Have a detergent and emulsifying effect of bile on fats. They also increase absorption of fats in small intestines

Question 31

What does the hepatobiliary system do?

Answer 31

Liver produces and secretes bile by hepatocytes into canaliculi through the common bile duct into the duodenum/gallbladder until they form a common hepatic duct. Flow is in opposite direction to hepatic veins and arteries

Question 32

What controls the path of bile?

Answer 32

Sphincter of Oddi. Contracts to deliver bile to gallbladder and relaxes to deliver to duodenum

Question 33

What regulates sphincter relaxation?

Answer 33

CCK

Question 34

What does the gallbladder do?

Answer 34

Stores and distributes bile
Contracts to expel bile in response to CCK
Vagal stimulation causes weak contraction
Somatostatin and noradrenaline inhibit bile acid secretion

Question 35

What are the non-biliary functions of the liver?

Answer 35

Metabolism of CHO, protein, fat: stores and releases CHO
Detoxification: removal of ammonia, ethanol and drug transformations
Immune system: removal of intestinal bacteria from portal blood so there is none in systemic circulation