Pancreas / Diabetes Flashcards
3 acute consequences of diabetes
1) Polyuria
2) Polydipsia
3) Polyphagia
How does Insulin deficiency cause the 3Ps? (flow chart)
Insulin deficiency (eg. B cells not working) results in:
1) Decreased glucose uptake by cells → Increase Hepatic glucose output
Cells are not taking up glucose (due to low insulin), as a result Liver wants to release more glucose into blood to increase glucose uptake
2) Results in Hyperglycemia (excess glucose in blood) and Glucosuria (glucose in urine)
3) Glucosuria causes osmotic diuresis
Glucose in urine draws water into collecting ducts
Water follows glucose
4) Resulting in Polyuria (excess urine production)
5) Glucose deficiency causes Polyphagia (excessive appetite)
6) Polyuria → causes Polydipsia (extreme thirst)
7) Dehydration decreases blood volume → Peripheral circulatory failure → Renal failure + Low cerebral blood flow → Death
Why does rapid breathing and fruity breath occur during diabetes?
Without insulin and hence cells cannot take up glucose, body breaks down fat as fuel
Lipolysis occurs: TGL converts to Free Fatty acid, producing glycerol and Ketones
Ketones make blood more acidic → Body compensates by combining H+ with HCO3 bicarbonate to form Carbonic acid → Carbonic acid breaks down to CO2 and H2O → causing rapid breathing
Ketone body (Acetone) causes fruity breath
How does muscle wasting occur in Diabetes?
Proteins and Amino acids are broken down to glucose, treated as energy stores
Describe the process of insulin release in B cells
1) Glucose enters B cell via GLUT-2 transporter via passive facilitated diffusion
2) Glucose is phosphorylated to Glucose-6-phosphate
3) Glucose-6-phosphate converts to ATP
4) ATP acts on ATP-sensitive K+ channel, closing it. This causes high K+ concentration in cell aka depolarisation
5) Depolarisation stimulates voltage-gated Ca2+ channel to open. Ca2+ enters cell
6) Ca2+ as a secondary messenger causes vesicles of insulin to be released
