Pancreas and Liver Physiology

Question 1

What occurs in the endocrine part of the pancreas?

Answer 1

Produces hormones such as insulin or glucagon

Question 2

What is the exocrine function of the pancreas?

Answer 2

Acts on the small intestine to assist with the initial stages of digestion

Question 3

What is the function of pancreatic juice?

Answer 3

Breaks down macromolecules so they can be more easily absorbed by the small intestine

Question 4

In what species does the pancreatic duct join with the bile duct before joining the duodenum?

Answer 4

Sheep and Goats

Question 5

What makes up pancreatic juice?

Answer 5

HCO3- and Cl-

Question 6

What enzymes are found in the pancreatic juice?

Answer 6

Lipase, amylase and Protease

Question 7

What is the function of Trypsin?

Answer 7

To activate all the enzymes (it’s secreted in its inactivated form trypsinogen)

Question 8

What is Autocatalysis?

Answer 8

the process where the reaction product is also the catalyst for the reaction

Question 9

Where is trypsin firmed?

Answer 9

Trypsin is formed in the duodenum by enteropeptidase

Question 10

Whya re enzymes secreted in their inactive forms?

Answer 10

so taht they don’t break down tissue

Question 11

What is the function of HCO3-

Answer 11

to make the ingesta alkaline when it enters the duodenum

Question 12

Why is it important the ingesta from stomach is alkaline?

Answer 12

-Preventing injury to mucosa
-Providing optimal pH for enzymatic activity

Question 13

What is the Cephalic phase?

Answer 13

changes in digestive activity that takes places before the ingesta enters the stomach

Question 14

What is the gastric phase?

Answer 14

Changes in the digestive tract and motility/ secretion in the stomach

Question 15

What is there an increase of in pigs and horses when there is increased enzyme secretion?

Answer 15

an increase of ion and water secretion

Question 16

What occurs during the intestinal phase?

Answer 16

Chyme entering the duodenum causes increases in pancreatic secretion
- This is regulated by CCK and secretin

Question 17

Where is Secretin released?

Answer 17

By S cells in the duodenum as a response to increased acidity in the gut (stimulates HCO3- secretion)

Question 18

What is Cholecystokinin (CCK)?

Answer 18

» released when FAs and peptides/amino
acids increase in duodenum
» stimulates pancreas to increase enzyme
secretion
» increased enzymes = increased ingesta
degradation
» = increased products of digestion

Question 19

What other organ does Cholecystokinin (CCK) act on?

Answer 19

The bile duct, causing it to release more bile secretion

Question 20

What is the role of the liver?

Answer 20

absorbs nutrients from the small intestine and releases them into the bloodstream, it also inactivates substances such as drugs/ alcohol

Question 21

What is the role of the gall bladder?

Answer 21

site of storage of bile when there is no digestuion

Question 22

Whata re bile salts prodcued from?

Answer 22

cholesterol

Question 23

Sphincter of Oddi

Answer 23

Band of muscle that controls entry into the duodenum from the bile duct

Question 24

What is the function of bile salts?

Answer 24

Help to digest fat in the small intestine

Question 25

What happens to bile salts in the small intestine?

Answer 25

Bile salts are not lipid soluble = not absorbed by diffusion from the SI - They function throughout the entire length of the SI before being absorbed at its end - Absorbed bile salt molecules are returned to the liver = enterohepatic circulation

Question 26

What regulates bile secretion?

Answer 26

Parasympathetic activity, mediated via vagal nerves and secretin Most important factor determining the volume of bile is the amount of bile salts in the bile canaliculi - when the concentration of bile salts in the portal blood rises the amount of bile released from the hepatocytes increases

Question 27

What stimulates the release of secretin?

Answer 27

Release stimulated by acidic duodenal content * Causes increase of HCO3 - from pancreas * Causes increase of bile production

Question 28

Why is there a constant rate of secretion of pancreatic juice in ruminants?

Answer 28

The abomasum receives a continuous flow of food

Question 29

When do cats and dogs have the largest increase in pancreatic juice production?

Answer 29

Straight after eating

Question 30

What does the bicarbonate concentration in horses provide the ideal conditions for?

Answer 30

Fermentation in the colon and caecum

Question 31

Why may horses struggle to secrete enzymes?

Answer 31

Produce 35-40 L of pancreatic juice so the flow rate is too high

Question 32

When is bile production highest?

Answer 32

When the bile salts recirculate after a meal

Question 33

Why is it important that dogs/cats have a gallbladder

Answer 33

They have intermittent meals so they need to store their bile