Pancreas

Question 1

Define glycolysis

Answer 1

Breakdown of glucose into smaller compounds which generates energy

Question 2

Define glycogenesis

Answer 2

The formation of glycogen from glucose

Question 3

Define glycogen

Answer 3

Glucose polymer

Question 4

Define glycogenolysis

Answer 4

Glycogen breakdown to glucose

Question 5

At what concentration is hyperglycaemia defined?

Answer 5

Above 30 mM

Question 6

Explain osmotic diuresis

Answer 6

Occurs with high blood glucose. Lots of pee as the body tries to excrete glucose. Can also lead to excessive thirst

Question 7

Define gluconeogenesis

Answer 7

The formation of glucose from non-carbohydrates substrates like lactate and amino acids

Question 8

Explain 2 mechanisms of hepatic glucose production

Answer 8

Glycogenolysis

Gluconeogenesis

Question 9

What concentration of blood glucose defines hypoglycaemia

Answer 9

2-3 mM

Question 10

Name 3 factors that lower blood glucose levels

Answer 10

Transport of glucose into cells for energy production
Transport of glucose into cells for storage as glycogen
Urinary excretion of glucose

Question 11

Define an islet of langerhan

Answer 11

The secretory cells of the pancreas

Question 12

Name the 2 hormones that are secreted by the islets of langerhans and the related cells

Answer 12

Alpha cells - glucagon

Beta cells - insulin

Question 13

Which hormone secreted by the pancreas is catabolic?

Answer 13

Glucagon

Question 14

Glucose is hydrophilic. How does it enter the cell?

Answer 14

Through a transport protein

Question 15

What is a GLUT

Answer 15

Glucose transporter

Question 16

Location of GLUT 1?

Answer 16

Blood brain barrier

Question 17

Which glucose transporter starts to work at higher concentrations of glucose? 15-20 mM

Answer 17

GLUT 2

Question 18

Activation of GLUT 2 (found on the liver and pancreas) initiates what events?

Answer 18

Pancreas - insulin secretion

Liver - removal of glucose from the blood

Question 19

Which GLUT is found in all tissues?

Answer 19

GLUT 3

Question 20

Which GLUT, found on muscle and fat cells, can be increased in expression with resistance training?

Answer 20

GLUT 4

Question 21

Which 2 glucose transports are the most sensitive to glucose?

Answer 21

1 and 3

Question 22

What effect does insulin have on GLUT4

Answer 22

Stimulates glucose uptake by GLUT4 by promoting exocytosis, causing the vesicles to deposit the transporter into the cell membrane of myocytes and adipocytes

Question 23

Does insulin promote the synthesis or breakdown of proteins and fats?

Answer 23

Synthesis

Question 24

What acts on the pancreas to get it to start secreting insulin?

Answer 24

GLP (a gastrointestinal hormone).

GLP is released on food intake

Question 25

Other than high blood glucose and food intake, what 2 other factors can stimulate insulin secretion?

Answer 25

High blood amino acid concentration | Parasympathetic stimulation

Question 26

Name the 2 main sites of action of glucagon?

Answer 26

Liver and adipose tissue

Question 27

Is glucagon catabolic or anabolic?

Answer 27

Catabolic

Question 28

Low blood glucose levels stimulate the pancreatic alpha cells to secrete what?

Answer 28

Glucagon

Question 29

Which hormone stimulates gluconeogenesis?

Answer 29

Glucagon

Question 30

To mobilise glucose from its storage form, glucagon promotes which process?

Answer 30

Glycogenolysis

Question 31

Other than glucagon and adrenaline, which other 2 molecules increase blood glucose levels?

Answer 31

Glucocorticoids | Growth hormone

Question 32

Explain type 1 diabetes

Answer 32

It is an autoimmune condition that causes the destruction of the beta cells of the pancreas, inhibiting insulin secretion

Question 33

What treatment option is used for gestational diabetes?

Answer 33

Recombinant human insulin injections. (Same as for type 1)

Question 34

Explain 2 non-pharmacological treatment option for diabetes?

Answer 34

- exercise (increases GLUT4 expression) - diet (limiting sugary foods, non processed, vegetables, lean meat) - weight loss

Question 35

Explain the use of a biguanide

Answer 35

It is an oral hypoglycaemic | Inhibits glucose output from the liver and increases glucose uptake by the muscles

Question 36

Name a biguanide

Answer 36

Metformin

Question 37

What is an advantage of using a biguanide? Give 1 drug example.

Answer 37

Does not cause hypoglycaemia | Example= metformin

Question 38

Which oral hypoglycaemic drug class requires functioning beta cells?

Answer 38

Sulfonylureas

Question 39

Explain the MOA of sulfonylureas

Answer 39

Stimulates insulin secretion

Question 40

Gliclazide and tolbutamide are examples of which drug class?

Answer 40

Sulfonylureas

Question 41

Potential problem with sulfonylureas?

Answer 41

Can cause hypoglycaemia. Can also stimulate appetite and weight gain

Question 42

Explain how thiazolidinediones reduce insulin resistance

Answer 42

It is an agonist for a nuclear insulin receptor. It enhances the uptake of fatty acids which lowers blood glucose - since free fatty acids increase gluconeogenesis

Question 43

Give an example of a thiazolidinedione

Answer 43

Rosiglitazone

Question 44

Give the MOA of Byetta

Answer 44

It is a venom derived peptide that is a GLP agonist. Used in T2DM

Question 45

Name 2 mechanisms that the body can use to decrease blood glucose levels

Answer 45

- transport of glucose from the blood into cells | - urinary excretion

Question 46

How does insulin affect GLUT 4 expression

Answer 46

In the presence of insulin, vesicles containing GLUT 4 move to the cell membrane and deposit / undergo exocytosis and the transporter is inserted into the membrane of adipose and muscle cells

Question 47

Name the two actions of GLUT 4 (one on fat and one on muscles)

Answer 47

Muscles - glut 4 activation increases glycogen synthesis and also increase glucose use in the muscles Fat - promotes lipogenesis (building of new fat)

Question 48

What 3 actions does insulin stimulate in the liver

Answer 48

- glycogen synthesis | - inhibits gluconeogenesis and glycogenolysis

Question 49

Is insulin secreted in the fed or fasted state

Answer 49

Fed

Question 50

Explain the action of GLP

Answer 50

GLP is a hormone secreted by the hormone in response to food intake. It acts on the pancreas to stimulate the beginning of insulin secretion

Question 51

Does the parasympathetic system increase or decrease insulin secretion?

Answer 51

Increase

Question 52

When is glucagon secreted

Answer 52

In fasting state

Question 53

Which hormone, glucagon or insulin, increases glycogenolysis ang gluconeogenesis?

Answer 53

Glucagon

Question 54

Which drug class requires functioning beta cells?

Answer 54

Sulfonylureas (e.g. gliclazide)

Question 55

What affect does insulin have on fatty acids and amino acids?

Answer 55

Promotes their cellular uptake and conversion into storage forms (triglycerides and protein)

Question 56

Define gluconeogenesis

Answer 56

Conversion of amino acids into glucose in the liver

Question 57

True or false. Insulin promotes protein synthesis

Answer 57

True

Question 58

Explain how glucose and amino acids act on the pancreatic beta cell to stimulate insulin secretion.

Answer 58

Glucose and amino acids enter the cell via GLUT 2. They are converted to ATP ATP closes K channel which depolarises the cell. Depolarisation opens Calcium channel. Calcium facilitates the exocytosis of insulin vesicles.

Question 59

What happens after a high protein meal?

Answer 59

Amino acids act on beta cells to stimulate insulin secretion. Insulin then lowers blood amino acid levels by promoting protein synthesis

Question 60

Does the brain need insulin to access glucose?

Answer 60

No

Question 61

How can hyperglycaemia be aggravated by protein degradation in diabetic patients?

Answer 61

Due to reduced insulin, protein metabolism becomes catabolic. This increases blood amino acid concentration. These amino acids can then be used by the liver for gluconeogenesis, producing even more glucose and raising BG levels