Pancreatic and Bile Secretion

Question 1

Describe the liver

Answer 1

Largest gland in the body
Produces bile
Comprises 4 lobes

Question 2

What are liver lobules?

Answer 2

Hexagonal structural and functional units
Filter and process nutrient-rich blood
Composed of plates of hepatocytes (liver cells) • Longitudinal central vein

Question 3

What is the portal vein?

Answer 3

Blood from small intestine that goes through the liver because liver breaks down anything toxic from small intestine

Question 4

Where are the bile ducts?

Answer 4

Around the edges of the liver

Question 5

Where does blood come into the liver?

Answer 5

Through portal vein into lobule, passes by hepatocytes

Question 6

What are sinusoids?

Answer 6

Canals moving in between hepatocytes, substances can go in and out of them

Question 7

What happens once blood has been passed through the sinusoid?

Answer 7

Once cleaned it goes into the central vein and then into the hepatic vein

Question 8

What are hepatocytes involved in?

Answer 8

Bile production

Question 9

What is the process of making bile?

Answer 9

Hepatocytes->bile canaliculi (passageways move in between hepatocytes, gather up bile)->bile ductules->bile ducts

Question 10

What does a hepatocyte look like

Answer 10

Sinusoidal Blood
Apical membrane tight junction, connected to “basolateral membrane”
Sinusoidal blood

Question 11

How much bile is produced per day?

Answer 11

800-1000mL

Question 12

What is the pH of bile?

Answer 12

7.6-8.6

Question 13

What does bile contain?

Answer 13

Bile salts
Bilirubin
Cholestrol, neutral fats, phospholipids, and electrolytes

Question 14

What are the functions of bile?

Answer 14

Lipid assimilation
Elimination
Neutralise gastric acid and provide optimum pH for pancreatic enzymes

Question 15

What are bile salts?

Answer 15

Cholesterol derivatives that function in fat

Question 16

What are the bile ducts?

Answer 16

Right and left hepatic ducts of liver
Cystic duct
Common hepatic duct
Bile duct and sphincter
Accessory pancreatic duct
Main pancreatic duct and sphincter
Hepatopancreatic ampulla and sphincter

Question 17

Where is the main pancreatic duct?

Answer 17

In the pancreas heading towards the tail of the pancreas

Question 18

Where is the Hepatopancreatic ampulla and sphincter?

Answer 18

Between the pancreas and the duodenum

Question 19

What is the appearance of the gallbladder?

Answer 19

Thin walled, pear-shaped, muscular sac on the ventral surface of the liver

Question 20

What is the function of the gallbladder?

Answer 20

Stores and concentrates bile by absorbing its water and ions

Question 21

What does the gallbladder release?

Answer 21

Bile via the cystic duct which flows into the bile duct

Question 22

What are gallstones also called?

Answer 22

Cholelithiasis

Question 23

What do gallstones account for?

Answer 23

95% of biliary tract disease

Question 24

How are gallstones formed?

Answer 24

Form if bile contains insufficient bile salts or excessive cholestrol

Question 25

What does cholestrol do to form gallstones?

Answer 25

Crystallises

Question 26

How are gallstones treated?

Answer 26

With drugs, lithotripsy or surgery

Question 27

What is bile secretion regulated by?

Answer 27

Bile salts in enterohepatic circulation | Secretin from intestinal cells exposed to HCL and fatty chyme

Question 28

What is gallbladder contraction stimulated by?

Answer 28

``` Cholecystokinin (CCK) from intestinal cells exposed to proteins and fat in chyme Vagal stimulation (minor stimulus) ```

Question 29

What does CKK cause?

Answer 29

The heptopancreatic sphincter to relax

Question 30

What is the pancreas endocrine functions?

Answer 30

Pancreatic islets secrete insulin and glucagon

Question 31

What is the pancreas exocrine functions?

Answer 31

Acini (clusters of secretory cells) secrete pancreatic juice | Zymogen granules of secretory cells contain digestive enzymes

Question 32

How much pancreatic juice is produced?

Answer 32

1200-1500mL per day

Question 33

What does pancreatic juice contain?

Answer 33

Electrolytes (primarily HCO3-) | Enzymes

Question 34

What are the pancreatic enzymes?

Answer 34

Amylase, lipases, nucleases are secreted in active form but require ions or bile for optimal activity

Question 35

What happens when proteases is secreted?

Answer 35

Secreted in inactive form and activated in duodenum

Question 36

What is trypsinogen activated to?

Answer 36

Trypsin

Question 37

What is trypsinogen activated by?

Answer 37

Brush border enzymes

Question 38

What does trypsin activate?

Answer 38

Procarboxypeptidase and chymotrypsinogen

Question 39

What does CCK induce?

Answer 39

The secretion of enzyme-rich pancreatic juice by acini

Question 40

What does secretin cause?

Answer 40

Secretion of bicarbonate-rich pancreatic juice

Question 41

What also causes the release of pancreatic juice?

Answer 41

Vagal stimulation

Question 42

What does chyme entering the duodenum cause?

Answer 42

Release of cholecystokinin (CCK) and secretin from duodenal enteroendocrine cells

Question 43

Where are CCK and secretin released into?

Answer 43

Bloodstream

Question 44

What does CCK induce?

Answer 44

Secretion of enzyme-rich pancreatic juice

Question 45

What does secretin cause?

Answer 45

Secretion of HCO3- rich pancreatic juice

Question 46

What stimulates the liver to produce bile more rapidly?

Answer 46

Bile salts and to a lesser extent secretin

Question 47

What does CCK cause?

Answer 47

Gallbladder to contract and hepatopancreatic sphincter to relax; bile enters duodenum

Question 48

What causes weak contractions of gallbladder?

Answer 48

During cephalic and gastric phases, vagal nerve stimulation

Question 49

What is the portal triad?

Answer 49

Portal vein Hepatic artery Bile duct