Pancreatic Hormones Flashcards
What is the exocrine function of the pancreas?
Digestive gland/enzymatic secretion
What is the endocrine function of the pancreas?
Hormone synthesis (insulin)
Where do the exocrine products of the pancreas go?
Through the duct system into the duodenum
What is the innervation of the islets of Langerhans?
Symp and para
What are the islet cells types?
Alpha Beta Delta Epsilon PP
What do alpha cells secrete? (2)
Glucagon
Proglucagon
What do beta cells secrete? (5)
Insulin C-peptide Proinsulin Islet amyloid polypeptide GABA
What do delta cells secrete?
Somatostatin
What do epsilon cells secrete?
Ghrelin
What do PP/F cells secrete?
Pancreatic polypeptide
What type of hormone is insulin?
Peptide
How is insulin made?
Translated as proproinsulin
Cleaved to proinsulin, then packaged into secretory granules with enzyme to turn into insulin
What links the alpha and beta chains of preproinsulin?
disulfide bonds
What is C peptide?
Fragment of preproinsulin
What is the half-life of insulin?
3-5 minutes
The release of insulin is what? (constant, variable etc)
Pulsatile and periodic
What are the three ways that the release of insulin is regulated?
Neural
Hormonal
Nutrient/ion
What is the nerve that innervates the islet cells?
Vagus
What is the most potent stimulator of insulin release?
Glucose
What ion’s influx is induced by glucose?
Ca
What does increased ATP/ADP ratio close in a cell? What does this cause?
Inhibits K channel in cells
This causes depolarization
What happens when cells are depolarized from the K channel closing?
Ca rushes in, causing insulin secretion
What are the receptors that stimulate islet cells? What is the neurotransmitter? G protein?
M3 receptors
ACh
Gq
What is main the amplifier of insulin secretion?
Glucagon-like peptide (GLP1)