HUBS L29 Homeostasis of plasma glucose and Diabetes Mellitus Flashcards
(20 cards)
What is the normal fasting plasma glucose concentration?
3.5 to 6 mmol/L
What is the normal non-fasting plasma glucose concentration?
3.5 to 8 mmol/L
Why is blood glucose concentration so important?
Because brain cells rely mainly on glucose for energy
Can other cells use energy sources besides glucose?
Yes, other cells can use alternative fuels like fats when glucose is low
What can happen if blood glucose stays high for a long time?
It can damage various organs over time
What do 99% of pancreatic cells do?
They are in acini and secrete digestive enzymes into ducts (exocrine function)
What are the small clusters of endocrine cells in the pancreas called?
Pancreatic islets or Islets of Langerhans
What hormone do alpha cells of the pancreas secrete?
Glucagon
What is the effect of glucagon on blood glucose levels (BGL)?
It increases blood glucose levels.
What hormone do beta cells of the pancreas secrete?
What is the effect of insulin on blood glucose levels (BGL)?
What is the effect of insulin on blood glucose levels (BGL)?
It reduces blood glucose levels
What type of hormone is insulin?
A protein hormone
Where is insulin initially synthesized in beta cells?
On the rough endoplasmic reticulum (RER) as a preprohormone with A, B, and C chains
What happens to the C chain of insulin during processing?
It is removed in the Golgi apparatus, and insulin is packaged into secretory vesicles
When is insulin (and C peptide) released from beta cells?
When blood glucose levels (BGLs) rise
What does insulin do to correct hyperglycaemia (high blood glucose levels)?
It facilitates glucose uptake into cells of most body tissues
What happens without insulin?
Most cells can’t use glucose for energy, and blood glucose levels remain too high
What transporter allows glucose to enter muscle cells in response to insulin?
GLUT4 (insulin-dependent glucose transporter)
