Main Hormones Regulating Blood Glucose Levels

Question 1

Which organ is most dependent on extracellular glucose concentration

Answer 1

Brain

Question 2

Which cells are most damaged by hyperglycaemia

Answer 2

Endothelial cells

Question 3

Normal blood sugar level

Answer 3

4-5.4 mmol/L before eating
Less than 8 mmol/L 2 hrs after eating

Question 4

What molecules is glucose converted to for storage

Answer 4

Glycogen
Triglycerides

Question 5

What is the process of insulin secretion

Answer 5

Glucose enters beta cells -> glucokinase senses glucose -> ATP/ADP ratio incr -> ATP sensitive K channels close -> membrane depolarisation -> voltage gated Ca channels open -> inctracellular Ca incr -> insulin containing granules secreted

Question 6

What cells secrete insulin

Answer 6

Beta cells

Question 7

Increase in what intracellular concentration triggers insulin secretion in beta cells

Answer 7

Calcium

Question 8

What is the role of glucokinase in insulin secretion

Answer 8

Glucose sensor

Question 9

Which amino acids can stimulate insulin release

Answer 9

Leucine
Arginine

Question 10

How do amino acids increase intracellular ATP/ADP ratio

Answer 10

Catabolism

Question 11

What molecules can cause insulin release other than glucose

Answer 11

Leucine
Arginine
Glucagon like peptide 1 GLP1
Glucose dependent insulinotrophic peptide GIP
Fatty acids
ACh
Cholecystokinin

Question 12

How do muscles and adipocytes take up glucose in response to insulin

Answer 12

GLUT4 translocates to the plasma membrane

Question 13

What enzyme is activated in muscles in response to insulin

Answer 13

Glycogen synthase

Question 14

What does glycogen synthase kinase do

Answer 14

Inhibits glycogen synthase

Question 15

What does insulin stimulate in muscles

Answer 15

Glucose uptake
Glycogen synthesis

Question 16

What does processes does insulin stimulate and inhibit in adipocytes

Answer 16

Stim Lipogensis
Inhibit lipolysis

Question 17

How does insulin stimulate lipogenesis

Answer 17

Incr glucose uptake
AcetylCoA carboxylase activation
Incr lipogenic gene expression

Question 18

How does insulin inhibit lipolysis in adipocytes

Answer 18

Inhibits hormone sensitive lipase preventing hydrolysis of triglycerides

Question 19

What molecule inhibits beta oxidation of FFAs in adipocytes

Answer 19

Malonyl CoA

Question 20

What processes does insulin effect in the liver

Answer 20

Incr glucose uptake
Incr glycogenesis
Incr lipogenesis
Inhibits Gluconeogenesis

Question 21

Which processes are activated in the post absorptive state

Answer 21

Processes releasing glucose and fatty acids

Question 22

Which hormones are active in the post absorptive state

Answer 22

Glucagon
Insulin counter regulatory hormones

Question 23

Which cells secrete glucagon

Answer 23

Alpha cells of islets of langerhans

Question 24

What stimulates glucagon secretion

Answer 24

Low blood glucose concentration
Increased blood amino acids
Exercise

Question 25

What inhibits glucagon secretion

Answer 25

Hyperglycaemia GLP-1 Somatostatin Insulin Zinc

Question 26

What type of receptor is the glucagon receptor

Answer 26

G protein coupled receptor

Question 27

What is the key signalling cascade activated by glucagon

Answer 27

Adenylyl cyclase pathway

Question 28

How can insulin effect glucagon dependent signalling

Answer 28

Switch off signalling

Question 29

Which organ does glucagon mainly act on

Answer 29

Liver

Question 30

Which processes does glucagon stimulate and inhibit

Answer 30

Stim glycogenolysis Inhibit glycogensis

Question 31

How does glucagon affect amino acid uptake in liver cells

Answer 31

Increase

Question 32

How does glucagon affect FA beta oxidation

Answer 32

Increase

Question 33

How does glucagon affect de novo lipogenesis

Answer 33

Inhibits

Question 34

What happens to excess acetyl CoA

Answer 34

Converted to ketone bodies

Question 35

What processes does glucagon increase in the liver

Answer 35

Glycogenolysis Gluconeogenesis Lipolysis

Question 36

What processes does glucagon inhibit in the liver

Answer 36

Glycolysis Glycogenesis Lipogenesis

Question 37

What hormones affect blood glucose concentration other than glucagon and insulin

Answer 37

Catecholamines Glucocorticoids Growth hormones Thyroid hormones GLP-1

Question 38

Which cells synthesise catecholamines

Answer 38

Chromaffin cells in adrenal medulla

Question 39

What molecules are catecholamines synthesised from

Answer 39

Phenylalanine Tyrosine

Question 40

Does adrenaline respond to hyper or hypoglycaemia

Answer 40

Hypo

Question 41

What molecules are corticosteroids formed from

Answer 41

Cholesterol

Question 42

What regulates glucocorticoid secretion

Answer 42

Hypothalamus/pituitary/adrenal axis

Question 43

Which hormone is important in resisting stress and inflammation

Answer 43

Glucocorticoids

Question 44

How does cortisol resist stress and inflammation

Answer 44

Maintains BP Suppresses inflammation

Question 45

Does cortisol increase or decrease blood sugar concentration

Answer 45

Increase

Question 46

What cells secret growth hormone

Answer 46

Somatotroph cells in anterior pituitary

Question 47

What hormones stimulate and inhibit growth hormone release

Answer 47

Stim by growth hormone releasing hormone Inhibited by somatostatin

Question 48

What receptors does growth hormone act on

Answer 48

GH receptor Prolactin receptor

Question 49

Which tissues have prolactin receptors

Answer 49

Liver Muscle Bone Adipose

Question 50

What is the effect of growth hormone in the liver

Answer 50

Incr production and uptake of IDL LDL HDL

Question 51

What is the overall effect of thyroid hormones

Answer 51

Increase basal metabolic rate

Question 52

How do thyroid hormones increase basal metabolic rate

Answer 52

Incr HbF and activity of mitochondria Stim carbohydrate metabolism Stim fat metabolism

Question 53

What are Incretins

Answer 53

Group of GI hormones secreted immediately after eating to regulate insulin secretion and decrease blood glucose

Question 54

What type of hormone is glucagon like peptide 1

Answer 54

Incretin

Question 55

What tissues does GLP-1 affect

Answer 55

Pancreas Skeletal muscles Liver Adipose Stomach