Flashcards in Lecture 37: Blood Glucose Concentration Deck (18):
The pancreas is an _____ and _____ gland.
In the pancreas, the ____ cells are important for insulin, and the ____ cells are important for glucagon.
As blood glucose level increases, beta cells secrete _____ into the bloodstream so that ____ _____ and the ____ take up glucose. The _____ is responsible for storing glucose as glycogen.
- Body Cells
Main role of insulin is to regulate ____ ____.
- Fuel storage
Beta cells are both the ____ and _____ of the blood glucose homeostatic system.
Target cells of insulin include:
- Muscle & Adipose (fat) Cells
- Liver cells
Too much glucose in the fat cells = storage of _______.
- Triglycerides (fat)
Once blood glucose concentration falls, the beta cells sense this and...
- Insulin is no longer secreted
Glucagon regulates ____ ____.
- Fuel release
Pancreatic islet ____ cells secrete _______ when the blood glucose concentration is low. The target cells are the ______ cells which catalyses the breakdown of _____, ______ and ketone synthesis.
What is the difference between glycogen and glucagon?
- Glycogen = stored form of glucose
- Glucagon = hormone
Hormones that also increase BGC (blood glucose concentration):
- Growth hormone
What mechanism does insulin use (simple)?
- Insulin binds to it's receptor
- It opens up a glucose channel
- Glucose enters cell through glucose channel
What mechanism does insulin use (complicated)?
- Insulin binds to it's receptor, and becomes phosphorylated
- Stimulates another protein to activate PI-3 kinase
- This binds to a storage vesicle of glucose transporters
- This transporter moves to the membrane
- Channel opens, glucose enters
- If the cell is inactive, glycogen is stored in cell
- If the cell is active, they can use glucose as an energy source
- This can only happen if there are working insulin receptors
What causes insulin resistance?
- Lipid accumulation
- No glucose channels in the membrane
- Insulin still binds to receptors but can't go into the cell
Long term insulin resistance leads to...
- Impaired beta cell function
- Beta cell compensation occurs and beta cells get bigger so they can pump out more insulin
Type I Diabetes Mellitus:
- Insulin producing beta-cells have been destroyed and insulin levels are low
- Glucose in urine
- High blood glucose
- Insulin injections