Lecture 12- Endocrine pancreas

Question 1

Pancreas functions?

Answer 1

Two functions

Digestive enzymes exocrine and hormones endocrine

Question 2

Hormones produced by pancreases?

Answer 2

Insulin, glucagon, ghrelin, somatostatin

Question 3

What do insulin and glucagon regulate?

Answer 3

Metabolism of carbohydrates, fats and proteins

Question 4

Plasma glucose levels?

Answer 4

Normally 3.3 to 6 mMol/Litre

Rising to 7-8 after a meal.

Question 5

At what blood glucose level will you got glycosuria?

Answer 5

When renal threshold exceeds 10 mMol/L

Question 6

Actions of insulin?

Answer 6

Anabolic

Anti gluconeogenic
Anti lipolytic
Anti ketogenic

Question 7

How is insulin synthesised?

Answer 7

Made in RER and sent to Golgi where secretory vesicles contain insulin and c peptide.
Vesicles undergo margination as they move to the cell membrane ready for exocytosis

Question 8

What is the role of KATP channels in insulin release?

Answer 8

When no glucose present channels open and get hyperpolarisation. When glucose present channels close and get depolarisation which is detected by voltage gated calcium channels. These channels open and calcium influx causes vesicles to be exocytosed. High ATP from glucose metabolism in cell shuts channels

Question 9

What type of receptor is that for insulin?

Answer 9

Tyrosinee kinase

Question 10

Actions of insulin on cell?

Answer 10

Causes glucose uptake. Leads to glycogen formation as well as pyruvate and fatty acids

Question 11

Glucagon actions?

Answer 11

Glycogenolytic
Gluconeogenic
Ketogenic
Lipolytic

Question 12

Insulin nand glucagon both undergo margination, what is it?

Answer 12

Movement of vesicles to cell surface

Question 13

Where does glucagon have its main effect?

Answer 13

Liver glycogenolysis

Question 14

Main difference in structure between glucagon and insulin?

Answer 14

Glucagon is rigid insulin is flexible

Question 15

When is glucagon used clinically?

Answer 15

Diabetic patient with hypoglycaemia cannot take oral glucose

Question 16

What is ketogenesis?

Answer 16

Producing ketone bodies using fatty acids and ketogenic amino acids

Question 17

What is diabetes characterised by?

Answer 17

Chronic hyperglycaemia leading to long term clinical complications.
Associated with elevated glucose levels in urine

Question 18

What glucose levels indicate diabetes?

Answer 18

Fasting glucose of over 7 and random glucose over 11.1

Question 19

Cause of type one diabetes?

Answer 19

Autoimmune destruction of pancreatic B cells.

Can be absolute where completely destroyed or relative where failure to secrete adequate amounts of insulin

Question 20

What happens with KATP channels and type 1 diabetes?

Answer 20

Insensitive to ATP so when glucose metabolised and ATP produced channels fail to shut and hyperpolarisation persists which prevents calcium influx and insulin release

Question 21

Type 2 diabetes cause?

Answer 21

Insulin secreted but peripheral resistance.

Defective insulin receptor
Defect in post receptor events
Excessive glucagon

Question 22

What causes type 2 diabetes?

Answer 22

Peripheral insulin resistance caused by a combination of genetic factors and environmental factors including obesity and sedentary lifestyle

Question 23

What happens with insulin resistance in the young?

Answer 23

Initially beta cells compensate. Eventually unable to maintain and finally their dysfunction leads to relative insulin deficiency and overt type 2 diabetes

Question 24

Overt vs subclinical diabetes.

Answer 24

Subclinical is early stage where glucose tolerance only abnormal with stress. Overt is advanced clinical stage