Pancreas Flashcards
Which area in the pancreas produces hormones?
Islets of Langerhans
Which hormones are involved in regulating blood glucose?
Insulin
Glucagon
What signals release of insulin?
Feeding - high blood glucose
Hormone of storage
What cells release insulin?
β-cells
What are the effects of insulin?
Insertion of Glut 4 channels => glucose uptake
Inhibition of breakdown of fatty acids
How is insulin synthesised?
1) Pre-proinsulin translation, cleavage, then pre-insulin folding
2) Proinsulin transported to Golgi
3) Proinsulin cleaved to produce insulin and C-peptide
What stimulates release of insulin?
1) Glucose enters β-cell by Glut 2 channel
2) Increase ATP
3) Closes K ATP channel
4) Membrane depolarisation
5) Opens Ca2+ channel => influx of Ca2+
6) Ca2+ binds to vesicle containing insulin => exocytosis
What signals release of glucagon?
Fasting - low blood glucose
What are the effects of glucagon?
Catabolic
Glycogenolysis
Gluconeogenesis
Lipolysis
What is diabetes mellitus?
Chronic hyperglycaemia => damage to small and large blood vessels
What are some sx of diabetes mellitus?
Polyuria
Polydipsia
Weight loss
Tiredness
What is type 1 diabetes?
Autoimmune destruction of β-cells resulting in absolute deficiency of insulin
How does type 1 diabetes present?
Rapid onset weight loss, polyuria and polydipsia
Elevated venous plasma ketones
Vomiting due to ketoacidosis
How is type 1 diabetes treated?
Exogenous insulin given by injection or pump
What is type 2 diabetes?
Insulin resistance
