Flashcards in Pancreatic Hormones Deck (79):
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?
What do alpha cells secrete? (2)
What do beta cells secrete? (5)
Islet amyloid polypeptide
What do delta cells secrete?
What do epsilon cells secrete?
What do PP/F cells secrete?
What type of hormone is insulin?
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?
What is C peptide?
Fragment of preproinsulin
What is the half-life of insulin?
The release of insulin is what? (constant, variable etc)
Pulsatile and periodic
What are the three ways that the release of insulin is regulated?
What is the nerve that innervates the islet cells?
What is the most potent stimulator of insulin release?
What ion's influx is induced by glucose?
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?
What is main the amplifier of insulin secretion?
Glucagon-like peptide (GLP1)
What is the effect of catecholamines on insulin secretion?
Increases secretion if bind Beta
Decreases if binds alpha
What is the effect of somatostatin on insulin?
What is the insulin receptor like?
Transcellular Y kinase
Mitogenic and metabolic
Can glucose diffuse across a cell membrane? If not, how does it get in the cell?
No, uses energy dependent transport
What is the effect of insulin receptor signalling?
Promotes translocation of receptors of glucose to the cell membrane
Where is GLUT 1 found? Function?
Where is GLUT 2 found? Function?
Pancreatic beta cells
Where is GLUT 3 found? Function?
Where is GLUT 4 found? Function?
Skeletal muscle, fat
Insulin mediated uptake
Where is GLUT 5 found? Function?
Which GLUT transporter is regulated by insulin
Which GLUT transporter is on the surface of pancreatic B cells?
What is the effect of insulin of glycogen synthesis?
What is the effect of insulin on glycogen breakdown?
What is the effect of insulin on protein synthesis?
What is the effect of insulin on triglyceride synthesis?
What is the effect of insulin on glycogenolysis?
What is the effect of insulin on ketogenesis?
What is the effect of insulin on gluconeogenesis?
What is the effect of insulin on amino acid uptake in muscle?
What is the effect of insulin on glycogen synthesis (3)?
1. Increases glucose uptake
2. Increases glycogen synthase activity
3. Inhibits glycogen phosphorylase
What are the three effect of insulin on triglyceride storage?
1. Promotes fFA uptake
2. Promotes esterification of fFA
3. Inhibits lipolysis
Which cells secrete glucagon?
Alpha cells, and in the gut
What is the effect of glucose on glucagon secretion?
What is the effect of catecholamines of glucagon?
Promote glucagon release
What type of innervation stimulates glucagon release (symp or para)?
Both symp and para
What is the effect of FA of glycogen release?
What type of receptors does glucagon bind to?
What is the effect of glucagon on glucose output? Ketone body output?
What is the effect of glucagon on gluconeogenesis? Insulin?
What is the effect of glucagon on glycogenolysis? Insulin?
What is the effect of glucagon on glycolysis? Insulin?
What are the three hormones that promote Triglyceride breakdown in the absence of insulin?
Where is the glucagon gene expressed?
Gut and pancreas
GLP1 is secreted when?
in response to glucose, lipids, and parasymp stimualatino
What is the effect of GLP1?
Promotes the production and secretion of both insulin and somatostatin
GLP1 promotes the growth of what cells?
What degrades GLP1?
Dipeptidyl peptidase 4 (DPP-4)
What produces amoylin (IAPP)? When is it released?
Released by same stimulators of insulin
What is the function of Amylin?
Decreases glucagon secretion and GI motility
What pancreatic cells produce somatostatin?
When is somatostatin produced?
In response to insulin release stimuli
What is the function of somatostatin? What is this mediated through?
Inhibits insulin secretion in a paracrine fashion through SSTR-5
What cells produce pancreatic polypeptide? What causes its release?
F or PP cells in the pancreas
Released with neuronal control
What is the function of pancreatic polypeptide?
Regulated exocrine function of the pancreas
What pancreatic cells produce Ghrelin?
What is the function of Ghrelin? (3)
Induces gastric emptying, acid secretion, and increases appetite
What allows intestinal cells to express GLP1 and GLP2? (What enzyme)
Express prohormone convertase 1
GLP1 is secreted in response to what? (3)
Glucose, lipids, and parasymp stimulation
What is the effect of GLP1 on the growth of beta cells?
What degrades GLP1?
What do catecholamines do to insulin secretion?
What does beta stimulation do to insulin secretion?
What does alpha stimulation do to insulin secretion?