22 - Pancreatic Hormones Flashcards
(25 cards)
What hormones are secreted by Pancres?
Insulin and Glucagon
What are the 2 types of tissue found in the pancreas?
Acini and
Islets of Langerhans (alpha beta delta)
Which type of cells control Insulin and amylin
Beta cells of Islets
Which type of cell control glucagon release?
Alpha cells of Islets (when are low)
Which type of cell control somatostatin release?
Delta cells
How is glucagon secretion controlled?
Amylin inhibts Insulin
Insulin inhibit glucagon
somatostatin inhibit Insulin and glucagon
How can glucagon affect the body?
Inc glycogeno-lysis - liver
Inc Gluconeogenesis - liver
What other organs/effects does glucagon have?
Inc heart stregth
Inc blood flow Kidneys
Inc bile secretion
Stop gastric juices
How can we also stimulate glucagon secretion?
With high [ ] of A.A
Glucagon will convert excess A.A to make gluc for tissues
When do we notice somatostatins level to be inc?
Inc glycemia
Inc a.a
Inc f.a
How does somatostatin work?
Its inhibitory…
it will act locally for islets selts stoping insuling and glucagon
Slow movement of stomach etc
Dec secretion / absorbtion in G.I.T
How does somatostattin work?
It inhibits hypothal ant G.H secretion
Role of insulin by it not being there =
Hypergylcemia.. acidosis.. etc
Synthesis of Insulin
Pre-proinsulin made in ER
Cleaved to Proinsulin in Golgi
Where does Insulin bind
To InsulinR
Which has 2 alpha 2 beta.. and it causes autophosphorylation of Tyr.K
Where does insulin not bind to R?
It will bind muscles/adipocytes but NOT neurons in the brain
How does glucose cause the uptake in liver?
1) Enzymatic stimulation causing glycogen synthase
2) Liver phosphorylase inactivation
3) Glucose uptake
How does insulin affect Gluco-neogenesis
Dec enzymes that would causes it
or decrease the release of a.a for it to start making glucose
Why doesn’t the brain need insulin?
It is permeable to glucose
How does insulin affect fat storage?
Insulin inc. usage of gluocse
Decrease break down of fat
Promote synthesis of fat ( convert excess in liver)
Why do we need to prevent hyperglycemia?
If you have inc gluc
1) it inc osmotic P in ECF => dehydration
2) You loose gluc in urine.. leads to loss of fluid
3) Inc gluc longterm = tissue damage
What are the effects of insulin on genes?
It promots protein synthesis and storage Fxn insulin: -> Transports A.A into cells -> Promote translation of mRNA ->Inc transcription of selective genes -> stops breakdown of proteins -> Decrease liver gluconeogenesis
What amino acid is able to stimulate insulin secretion?
Lysine and Arginine
Gives 4 names of hormones that have an effect on mechanism of insulin
G.H
Cortisol
Glucagon
Epi
