Pancreas Endocrinology Flashcards
(24 cards)
What is the exocrine function of the pancreas?
Digestive enzyme secretion into the GIT
What is the endocrine function of the pancreas?
Hormone secretion from islets into blood
What cell types are found in the islets of Langerhans?
- Beta cells 75%
- Alpha cells 20%
- Gamma cells 5%
What do beta cells produce?
Insulin
What do alpha cells produce?
Glucagon
What do gamma cells produce?
Somatostatin
What is the structure of insulin?
Protein made of alpha and beta chains joined by two disulphide bridges
What is the acute phase of insulin secretion?
The release of stored insulin
What is the chronic phase of insulin secretion?
New synthesis of insulin and its release
What are the three key stimuli for insulin secretion?
- Glucose
- Amino acids
- Fatty acids
How does parasympathetic control affect insulin release?
Stimulates release
How does sympathetic control affect insulin release?
Inhibit’s release
What are the two major actions of insulin?
- Lowers glucose, fatty acids and amino acids in blood
- Promotes storage
How does insulin affect carbohydrate metabolism?
Increase glycolysis and glycogen synthesis
How does insulin affect lipid metabolism?
- Decrease lipolysis
- Increased FFA uptake into adipose tissue and actyl-CoA formation via glycolysis
How does insulin affect protein metabolism?
- Increased amino acid uptake and protein synthesis
- Decrease protein breakdown
What causes diabete mellitus?
Insulin deficiency resulting in:
- Decrease glucose uptake
Increase gluconeogenesis, glycogenolysis and lipolysis
What are the symptoms of diabetic ketosis?
- Acidosis
- Na/K imbalance
- Neural dysfunction
- Coma
- Death
What cause hyperinsulinism?
Overproduction or overdose of insulin
What are the effects of hyperinsulinism?
- Incoordination
- Tremors
- Unconsciousness
- Convulsions
Where is glucagon mainly produced?
In alpha cells
What are the main actions of glucagon?
- Increased glycogenolysis and gluconeogenesis
- decrease glycogen synthesis
Where is comatostatin produced?
Gamma cells
What does somatostatin do?
Inhibits insulin, glucagon and all islet endocrine cells
