Pancreas and insulin

Question 1

what is glycogen?

Answer 1

stored reservoir of glucose

Question 2

TF: the CNS can substitute glucose

Answer 2

NO, therefore delivery is critical from the blood

Question 3

hypoglycaemia?

Answer 3

<2.5mmol/L

Question 4

normoglycemia? fasting value

Answer 4

3-5mmol/L

Question 5

normoglycemia? fed state?

Answer 5

7-8mmol/L

Question 6

hyperglycaemia?

Answer 6

> 10mmol/L

Question 7

What happens when a normal person eats something sugary?

Answer 7

transiently hyperglycaemic

Question 8

homeostasis of hyperglycaemia?

Answer 8

rise in blood glucose
insulin release from b-cells
lowers glucose in blood

Question 9

where does insulin act?

Answer 9

liver, muscle, adipocytes, CNS

Question 10

where does endogenous glucose production occur?

Answer 10

liver

Question 11

what is endogenous glucose production?

Answer 11

conversion of glycogen to glucose

or formation from food

Question 12

homeostasis of hypoglycaemia?

Answer 12

fall in blood glucose
glucagon release from a-cells
endogenous glucose production- mainly by liver, muscles and adipocytes

Question 13

how does pro-insulin become human insulin?

Answer 13

23 amino acids are removed from proinsulin.

Question 14

what are the 23 amino acids removed from proinsulin called?

Answer 14

C-peptide

Question 15

where does the conversion of proinsuilin–> insulin occur?

Answer 15

insulin secretion cells

Question 16

what happens to C-peptide?

Answer 16

released along side insulin

Question 17

what can we use c-peptide for?

Answer 17

measuring insulin levels- insulin has a short half life so C-peptide tells us how much has been released

Question 18

where is insulin located and stored?

Answer 18

B-cell secretory granules

Question 19

what is insulin complexed with? structure?

Answer 19

zinc

crystal

Question 20

half life of insulin?

Answer 20

3-5 minutes

Question 21

where is insulin metabolised?

Answer 21

the liver

Question 22

langerhans compose about ___% of the total pancreas.

Answer 22

1

Question 23

most of what the pancreas does is related to?

Answer 23

digestion

Question 24

δ-cells?

Answer 24

release somatostatin

Question 25

ε-cells

Answer 25

release ghrelin

Question 26

what is ghrelin

Answer 26

hunger hormone

Question 27

what do PP-cells in the pancreas release?

Answer 27

pancreatic polypeptide

Question 28

what does pancreatic polypeptide effect?

Answer 28

digestive system

Question 29

___% of the blood at any one moment is bathing the islets

Answer 29

25

Question 30

how are the islets distributed in the pancreas?

Answer 30

distributed throughout

Question 31

what nerves are the islets connected to? how?

Answer 31

enteric and vagus nerve | neutrally connected

Question 32

pathway 1 of insulin release?

Answer 32

glucose uptake by isle B-cells K channels close, depolarisation Ca2+ influx due to depolarisation insulin release by exocytosis

Question 33

pathway 2 of insulin release?

Answer 33

release of gut hormones from enteroendocrine cells e.g. GLP-1= rise in blood levels activation on the GLP-1 receptors on B-cells cell signalling insulin release

Question 34

for pathway 1 release of insulin is proportional to?

Answer 34

the amount of glucose in the blood

Question 35

how can drugs target pathway 1 of insulin release? e.g.?

Answer 35

target K channels closing and depolarisation insulin secretagogues- blocks K channels and causes insulin release whether or not glucose levels have gone up or not = hypoglycaemia

Question 36

how can drugs target the pathway 2 of insulin release?

Answer 36

block receptors on b-cells e.g. GLP-1 receptors

Question 37

explain how insulin lowers blood sugar?

Answer 37

insulin binds to receptor on cell. insulin receptor has endogenous kinase activity- switches kinase activity on when binds cascade this cascade switches on glucose transporter in the cell membrane AND adds more receptors to the membrane

Question 38

insulin is also a _____ factor

Answer 38

growth factor

Question 39

the endocrine actions insulin actions are considered to be ______

Answer 39

anabolic

Question 40

effects of insulin (5)

Answer 40

``` increases transport into cells converts glucose to glycogen in the liver decreases glycogen to glucose breakdown increases fat stores increases protein production ```

Question 41

hyperglycaemia is ______ induced

Answer 41

glucagon

Question 42

TF: fat can be broken down to make glucose precursors?

Answer 42

TRUE

Question 43

skeletal muscle influence of glucose homeostasis

Answer 43

glucose uptake | glucose utilisation

Question 44

GIT influence on glucose homeostasis

Answer 44

glucose uptake | incretin effect

Question 45

what is diabetes mellitus?

Answer 45

when pancreas does not produce enough insulin or when the body cannot effectively use the insulin it produces.

Question 46

type I diabets is a disease of the _____ cell.

Answer 46

beta

Question 47

type II- beta cells _____ and the alpha cells become _____ active. this causes?

Answer 47

fail more hyperglycaemia

Question 48

what cells is insulin desensitisation felt by

Answer 48

liver, skeletal an adipocytes

Question 49

ways to treat diabetes?

Answer 49

- promote loss through kidneys - delay absorption in GIT - promote insulin release - sentitize to action of endogenous insulin - replace islets

Question 50

why dont you want to usually promote loss of glucose through kidneys?

Answer 50

as it can cause hyper-osmotic shock

Question 51

non medical causes of hypoglycaemia?

Answer 51

inadequate, irregular food intake insulin overdose sulphonylurea overdose

Question 52

medical causes of hypoglycaemia?

Answer 52

insulinoma, hyperinsulinsm, post gastric bypass surgery if morbidly obese

Question 53

autonomic symptoms of hypoglycaemia?

Answer 53

hunger, sweating, shaking, increased HR, headache, nausea

Question 54

neuroglycopaenic symptoms of hypoglycaemia?

Answer 54

confusion, drowsiness, odd behaviour

Question 55

what is the first aid treatment for severe hypoglycaemia when oral glucose is not possible or desired?

Answer 55

glucagon therapy to induce hyperglycaemia

Question 56

what is the route for glucagon therapy?

Answer 56

i.v. s.c. i.m. must be reconstituted before use

Question 57

what is the effect of glucagon therapy?

Answer 57

acutely raises plasma glucose levels

Question 58

side effects of glucagon therapy?

Answer 58

headache | nausea

Question 59

what patients are hyperglycaemia inducing therapies used in?

Answer 59

hyperinsulinism or insulinomas

Question 60

what's diazoxide therapy?

Answer 60

hyperglycaemia inducing therapies reverses the effect of glucose on beta cells causes hyperpolariation not depolarisation stops Ca2+ influx and hence insulin release

Question 61

how is diazoxide therapy administered?

Answer 61

oral administration

Question 62

side effects of diazoxide therapy?

Answer 62

``` anorexia nausea vomiting hypotension oedema tachycardia arrhythmias ```

Question 63

what can prolonged diazoxide therapy cause?

Answer 63

hypertrichosis- excessive hair growth all over the body