Endocrine Pancreas

Question 1

Match each cell type of the pancreas to what it produces:

1. A cells
2. B cells
3. D cells
4. F cells

Answer 1

1. glucagon
2. insulin
3. somatostatin
4. pancreatic polypeptide

Question 2

Term for “nests” of cells in pancreas

Answer 2

Islets of Langerhans

Question 3

______ is for glucose mobilization/usage while ______ is for glucose storage.

Answer 3

glucagon
insulin

Question 4

What is the function of somatostatin?

Answer 4

inhibits endocrine pancreas (regulatory)
ALSO has paracrine action

Question 5

What is the function of pancreatic polypeptide produced by F cells?

Answer 5

inhibits endocrine pancreas (regulatory)

Question 6

Insulin’s effects are opposed by _________ hormones.

Answer 6

diabetogenic

Question 7

What are the 4 diabetogenic hormones which oppose insulin?

Answer 7

1. glucagon
2. cortisol
3. epinephrine
4. growth hormone

Question 8

What 4 things (not hormones) inhibit insulin?

Answer 8

1. somatostatin
2. exercise
3. stress
4. fasting

Question 9

List the 3 steps and structures of insulin synthesis.

Answer 9

Pre-proinsulin –> Proinsulin –> Insulin

Question 10

What has to occur for Proinsulin to be converted to Insulin?

Answer 10

C-peptide is cleaved

Question 11

What is clinically useful about C-peptide cleaved during insulin synthesis?

Answer 11

released in urine and used as marker for insulin production

Question 12

Proinsulin is (active/inactive) while insulin is (active/inactive).

Answer 12

inactive
active

Question 13

What two molecules inhibit the conversion of insulin from proinsulin?

Answer 13

1. pancreastatin
2. amylin

Question 14

Amylin is only in what 3 animal types?

Answer 14

1. cats
2. primates
3. dogs with insulinomas

Question 15

List the steps of glucagon synthesis.

Answer 15

Pre-proglucagon (inactive) –> Glucagon (active)

Question 16

What occurs for Pre-proglucagon to be converted to Glucagon?

Answer 16

signaling peptide is cleaved

Question 17

Insulin must bind to a _______ to have an effect.

Answer 17

receptor

Question 18

What is unique about insulin receptors?

Answer 18

have an alpha and beta subunit

Question 19

When insulin binds the its receptor, there is a (phosphorylation/dephosphorylation) of _______ on (alpha/beta) subunit which allows for its activation.

Answer 19

phosphorylation
tyrosine kinase
beta

Question 20

Match whether insulin increases or decreases the following:

1. glucose transport
2. blood glucose
3. gluconeogenesis
4. glycogen & triglyceride synthesis

Answer 20

1. increase
2. decrease
3. decrease
4. increase

Question 21

Glucagon uses a G__ pathway to activate _________.

Answer 21

s (stimulatory)
glycogenolysis

Question 22

List the order of Gs pathway glucagon uses to activate glycogenolysis.

Answer 22

Glucagon –> adenylate cyclase –> ATP –> cAMP –> PKA activated = glycogenolysis

Question 23

What 3 actions does glucagon have on the liver?

Answer 23

1. up gluconeogenesis
2. up glycogenolysis
3. down glycogen synthesis

Question 24

What does glucagon do to protein catabolism and lipolysis?

Answer 24

increases them

Question 25

In an insulin deficiency, what 2 things occur in the liver?

Answer 25

increased glycogenolysis + gluconeogenesis

Question 26

Insulin deficiency leads to hyperglycemia which leads to ________.

Answer 26

osmotic diuresis

Question 27

Osmotic diuresis as a result of insulin deficiency leads to what 3 things?

Answer 27

1. dehydration
2. hypovolemia
3. hypotension

Question 28

_______ inhibits insulin and glucagon to balance their levels in the body.

Answer 28

somatostatin

Question 29

What two things stimulate somatostatin?

Answer 29

amino acids
glucose