Internal Control Flashcards
What do alpha cells detect?
A drop in blood glucose
What do beta cells detect? How do they differ to alpha?
Detect a rise - they are smaller and more numerous
What are the three main sources of glucose entering blood?
- Absorption from gut following digestion of carbohydrates
- hydrolysis of stored glycogen
- conversion of non carbohydrates such as lactate, fats and amino acids
Where are the B cells situated in the pancreas?
Islets of langerhans
What do B cells synthesise?
Insulin
How does glucose enter beta cells
Facilitated diffusion via carrier proteins
Why do people with type II diabetes not usually recieve pancreas transplants?
They still produce insulin
Can be controlled with controlled diet and increased exercise
What is the second messaged model?
Cascade of reactions that happens after the first messenger that take effect inside of the cell
d explain how the secretion of ADH affects urine produced by the kidneys
Permeability of membrane/cells (to water) is increased; More water absorbed from/leaves distal tubule/collecting duct; Smaller volume of urine; Urine becomes more concentrated;
How does diabetes affect the nervous system?
- Damage to autonomic nervous system
- Pressure receptors don’t work as
well; - Damage to medulla
Describe the action of glucagon
- Attaches to receptors on target cells
- Activates enzymes involved in the conversion of glycogen to glucose
- Activates enzymes involved in the conversion of glycerol and amino acids into glucose
Describe the action of insulin
Attaches to receptors on the surfaces of target cells
Controls the uptake of glucose by regulating the inclusion of channel proteins in the surface membranes of target cells
Activating enzymes involved in the conversion of glucose to glycogen
What is glycogenesis?
The formation of glycogen from glucose
Where does glycogenesis occur?
Happens in the liver
What is glycogenolysis?
The breakdown of glycogen to release glucose
