14.2-14.4 Regulating Blood Glucose Concentration Flashcards
What are the main two functions of the pancreas?
- Exocrine gland
- Endocrine gland
What is the role of the pancreas as an exocrine gland?
This tissue is responsible for producing digestive enzymes and alkaline fluid known as pancreatic juice.
What three types of digestive enzymes does the exocrine gland produce?
1) Amylases: breaks down starch e.g pancreatic amylase
2) Proteases- breaks down proteins e.g trypsin
3) Lipases- breaks down lipids e.g pancreatic lipase
What is the role of the pancreas as an endocrine gland?
Producing insulin and glucagon.
- It contains small regions called islets of Langerhans
What are the different types of cells in the islets of Langerhans?
1) Alpha cells
2) Beta cells
What is the role of alpha cells? (Islet of Langerhans)
Alpha cells produce and secrete glucagon
What is the role of beta cells? (Islets of Langerhans)
Beta cells produce and secrete insulin.
What is glycogenolysis?
Glycogenolysis is when glycogen stored in the liver and muscle cells is broken down into glucose, increasing blood glucose concentration.
What is gluconeogenesis?
Gluconeogenesis is the production of glucose from non-carbohydrate sources.
E.g making glucose from glycerol and amino acids
What is glycogenesis?
Glycogenesis is the production of glycogen by converting excess glucose into glycogen.
Describe the process by which insulin is secreted.
1) When blood glucose concentration rises, glucose enters the cell by a glucose transporter.
2) The glucose is metabolised inside the mitochondria, resulting in the production of ATP.
3) The ATP binds to ATP-sensitive potassium channels and causes them to close.
4) As potassium ions can no longer diffuse out of the cell, the potential difference reduces to around -30mV and depolarisation occurs.
5) Depolarisation causes the voltage-gated calcium channels to open.
6) Calcium ions enter the cell and cause secretory vesicles to release the insulin they contain by exocytosis.
What is type 1 diabetes?
Type 1 diabetes is a condition caused by non-functioning beta cells in the islet of Langerhans as they are unable to produce insulin.
What is type 1 diabetes caused by?
Type 1 diabetes is caused by an autoimmune response where the body’s own immune system attacks the beta cells, the persons beta cells cannot make insulin
What is type 2 diabetes?
- Type 2 diabetes is a condition where patients cannot effectively use insulin and control their blood sugar levels.
- This is either because the person’s beta cells do not produce enough insulin or the person’s body cells do not respond properly to insulin (incentive to insulin)
- glycoproteins receptors malfunctioning
- normally seen in older people due to unhealthy lifestyle
How is type 1 diabetes controlled?
- insulin injections (insulin dependent)
- pancreas transplant
- stem cells to replace malfunctioning beta cells with healthy beta cells
