Lecture 33: Pancreatic Islets Flashcards
Where is insulin secreted from?
The beta cells of the pancreatic islets.
Where is glucagon secreted from?
The alpha cells of the pancreatic islets.
Where are the pancreatic islets found?
In the endocrine gland of the pancreas.
What is the ONLY fuel that the brain uses?
Glucose.
What are the two metabolic states the body can be in?
Fed state (cellular uptake of nutrients & anabolic metabolism - SYNTHESIS of glycogen, protein and fat)
Fasting state (mobilisation of nutrients and catabolic metabolism - BREAKDOWN of glycogen, protein and fat).
What is the reference range of BGL?
3.5 - 6 mmol/L
Which hormones lowers BGL and which one increases it?
Insulin decreases BGL, glucagon increases it.
Explain the process of returning to a homeostatic BGL after eating.
Digestion - carbs broken down to glucose - causes rise in BGL.
Beta cells secrete insulin.
Insulin targets cells in the liver, muscle and fat, causing them to take up glucose.
BGL decreases.
NOTE THAT FEEDFORWARD SECRETION OF INSULIN ALSO OCCURS.
How quickly does the effect of insulin start becoming apparent?
Milliseconds. (WS hormone)
What is hyperglycaemia?
High BGL
What is glycosuria?
Glucose in urine.
What is polyuria?
large volumes of urine
What is polydipsia?
Thirst
What is polyphagia?
Hunger.
What are the symptoms of Type I diabetes mellitus?
Hyperglycaemia, glycosuria, polyuria, polydipsia and polyphagia.
