The Endocrine Pancreas 2

Question 1

What type of hormone is glucagon?

Answer 1

Peptide hormone

Question 2

Where is glucagon made?

Answer 2

alpha cells in pancreatic islets

Question 3

What is the role of glucagon?

Answer 3

Raise blood glucose

Glucose-mobilising hormone

Question 4

Glucagon acts on what?

Answer 4

The liver

Question 5

What is the half life of glucagon?

Answer 5

5-10mins

Question 6

What hormones make up the counter-regulatory control system for glucose?

Answer 6

Glucagon
Epinephrine
Cortisol
GH

Question 7

When is glucagon most active?

Answer 7

Fasted state

Question 8

Glucagon binds to what?

Answer 8

G-protein coupled receptors linked to the adenylate cyclase/cAMP system

Question 9

What happens when glucagon binds to G-protein coupled receptors?

Answer 9

Phosphorylation of specific liver enzymes

Question 10

What is the effect of the Phosphorylation of specific liver enzymes by glucagon?

Answer 10

Increased Glycogenolysis
Increased gluconeogenesis
Formation of ketones from FAs (lipolysis)

Question 11

What happens to Liver glycogen in the presence of glucagon?

Answer 11

Conversion of glycogen to glucose

Question 12

What happens to lipids in adipose tissue in the presence of glucagon?

Answer 12

Lipids become free fatty acids and glycerol

Question 13

What happens to muscle cells in a low [Glucose] environment?

Answer 13

Use of glycogen

FAs/Breakdown of proteins to amino acids for energy

Question 14

What can the brain use for energy?

Answer 14

Glucose

Ketone bodies

Question 15

Glycogen is converted into what in muscles/

Answer 15

Pyruvate/lactate –> Glucose (gluconeogenesis)

Question 16

Amino acids in the plasma stimulate what?

Answer 16

Increased insulin and glucagon

Question 17

What is the benefit of a high protein meal with little carbohydrate stimulating Insulin AND glucagon?

Answer 17

Prevents hypoglycaemia following insulin release in response to aa.

Question 18

Stimuli that promote glucagon release?

Answer 18

Low [BG] (<5mM)
High [amino acids] .
sympathetic innervation and epinephrine, beta2 effect
Cortisol
Stress e.g. exercise, infection

Question 19

Stimuli that inhibit glucagon release?

Answer 19

Glucose
FFAs and Ketones
Insulin
Somatostatin

Question 20

What effect does increased parasympathetic (vagal) activity have on islet cells?

Answer 20

Increased insulin
(somewhat) increased glucagon
ANTICIPATORY DIGESTION

Question 21

What effect does increased sympathetic activity have on islet cells?

Answer 21

Increased glucose mobilisation
Increased Glucagon, epinephrine
Inhibited insulin

Question 22

Where is somatostatin secreted from?

Answer 22

D-cells (pancreas)

Hypothalamus

Question 23

What is the pancreatic action of somatostatin?

Answer 23

Inhibit GIT activity
Slow down absorption of nutrients
Prevent peaks in plasma concentrations

Question 24

What is a use of synthetic somatostatin?

Answer 24

Treating life threatening diarrhoea associated with gut/pancreatic tumours

Question 25

What is the paracrine effect of somatostatin?

Answer 25

Suppress release of glucagon and insulin

Question 26

What is the effect of somatostatin on the anterior pituitary?

Answer 26

Inhibits secretion of GH

Question 27

What is the other name of somatostatin?

Answer 27

GHIH - Growth Hormone Inhibiting Hormone

Question 28

What causes a stimulation of somatostatin release?

Answer 28

↑[aa]plasma | ↑[Glucose]plasma

Question 29

How is entry of glucose into muscle increased during exercise?

Answer 29

Increased insulin sensitivity | Insulin-independent ↑ in number of Glut-4 transporters

Question 30

How long does increased insulin sensitivity last after exercise?

Answer 30

Several hours

Question 31

How does the brain adapt in starvation?

Answer 31

Adapts to use ketones for energy

Question 32

How are nutrients provided in starvation?

Answer 32

Adipose tissue is broken down into fatty acids | Fatty acids -> Ketones

Question 33

Which store is depleted last in starvation? Why?

Answer 33

Protein - weakening, makes person vulnerable to infection

Question 34

What is the cause of T1DM?

Answer 34

Autoimmune destruction of pancreatic beta cells

Question 35

Why does diabetes cause ketoacidosis?

Answer 35

Lack of insulin depresses the uptake of ketone bodies, which are acidic

Question 36

What is considered an acid blood pH?

Answer 36

ph<7.1

Question 37

Why do tissues no longer respond normal levels of insulin in T2DM?

Answer 37

Abnormal response of insulin receptors | Reduction in insulin receptor numbers

Question 38

Typical risk factors for T2DM?

Answer 38

Obesity >40yrs High sugar/fat diet

Question 39

What is the initial treatment for T2DM?

Answer 39

Exercise | Dietary change

Question 40

What is the first line therapy for T2DM?

Answer 40

Metformin (oral hypoglycaemic drugs)

Question 41

How does Metformin work?

Answer 41

Inhibit hepatic gluconeogenesis | Antagonise glucagon action

Question 42

How do Sulphonylureas work?

Answer 42

Close Katp in B cells | Stimulate Ca2+ entry and insulin secretion

Question 43

What is the diagnostic test for DM?

Answer 43

Glucose tolerance test Ingest glucose after fasting [BG] is measured Elevation after 2hrs indicates DM

Question 44

What are the most common diabetes complications?

Answer 44

Retinopathy Neuropathy Nephropathy Cardiovascular disease

Question 45

Coma appears at what [BG] levels?

Answer 45

1.7mM

Question 46

Death occurs at what hypoglycaemia [BG]?

Answer 46

0.6mM

Question 47

At what [BG] is cortisol secreted?

Answer 47

3.2mM