Endocrin: Pancreas

Front 1

what are the targets of glucagon
what are the targets of insulin

Back 1

liver
adipose

Insulin: liver, fat, sk MM

Front 2

what does glucagon do to urea

Back 2

increased

**glucagon stimulates brakdown of aa to from glucose

Front 3

what does somatostatin do to glucagon

Back 3

decreased

**glucagon also inhibited by: glucose on blood, insulin, FA and ketoacids

Front 4

what are the 3 hormones secreted by the pancrease

Back 4

1. Glucagon
2. Insulin
3. Somatostatin (also comes from hypothalamus)

Front 5

is the secretion of the pancrease stim by the hypothalamic hypophyseal system

Back 5

nope, the secretion of inculin/glucagon by the pancreas is controlled humorally, ie by conc of substarte in the blood

Front 6

what all things release somatostatin

Back 6

hypothalamus
GI
Pancreas

Front 7

insulin is the hormone of what? while glucagon is the hormone of what

Back 7

Insulin: abundance. secreted when nutrients are in abundance, insulin helps us store this excess fuel

Glucagon: starvation, promotes mobilization of fuel stores whn nutrients are low

Front 8

are insulin/glucagon workind in a paracrine manner

Back 8

sure thing

Front 9

are insulin/glucagon counterregulatory?

Back 9

sure thing

*antagonists, when one is secreted the other is not

Front 10

nutrient flow through the GO stimulates the pancrease to do what

Back 10

release exocrine digestive enzymes and endocrine homromes

**hormones and digestion is released at same time

Front 11

so hormone secretion in the pancreas is stim by nutirent flow in GI, where are nutrients released to?

Back 11

the portal vein where they meet the products of digestion

**pancrease is in a great location for this fx

Front 12

what cell in the islet releases insulin, gluc, somatostatin, pancreatic polypeptide

Back 12

insulin: b
Glucagon: a
somatostatin: delta
pancreatic polypeptide: F

Front 13

where are hormones in the pancreas made and stored

Back 13

islet of lanterhan

a: glucagon
b: insulin
delta: somatostatin
F:pancreatic polypeptide

Front 14

do the cell types of the islets talk

Back 14

you bet, gap junctions btwn a, b and ab

Front 15

is insulin released as a prohormone

Back 15

yep, it has C peptide that needs to be cleaved

Front 16

what is the structure of insulin

Back 16

a chain and b chain

**also has c peptide in prohormone stage

Front 17

so insulin is a peptide hormone, what do we know about its synthesis and storage

Back 17

prepoinsulin
proinsulin

Packaged and stored in granules (proinsulin, C is sttached)

Front 18

what is in the secretory granule for insulin? what is required for granule movement?

Back 18

proinsulin, with C peptide. when released insulin and c are released in 1:1 ratio (insulin has super short half life)

**granule movemnt requires a good microtubule system

Front 19

how can we approximate the levels of insulin in circulation despite its SUPER short 1/2 life

Back 19

measure C protein, its released 1:1 and C stays aroun dlonger

Front 20

what is the most importatn insulinogogue? waht is the mech

Back 20

metabolism of glucose

*glucose enters the B cell in the islet of langerhan and is oxidized to make ATP
*ATP closes K channels
*this DEPOLARIZES the b cell
*depolarization opens Ca channels
*Ca signals isulin granules to be released

**insulinogogue stim insulin secretion. Others include: glucagon, GLP, AA, GH, Cortisol

Front 21

what is the mech of Glucose stim insulin secretion

Back 21

glucose enters the B cells in islets of langerhan and is oxidized to form ATP

ATP closes K channels --> DEPOLARIZATION

depolarization leads to Ca incerase

Ca signals exocytosis of granules that contain insulin

Front 22

what decreases the release of insulin

Back 22

blood glucose
somatostatin
NE, EPI

Front 23

what things stim insulin secretion

Back 23

glucose, AA, FA
Glucagon
GLP
Ach

Front 24

how can insulin modulators increase/decrease insulin release

Back 24

cAMP to icnrease Ca and cause exocytosis

PLC to alter cAMP levels

Front 25

so increase in glucose, FA, or AA will stim secretion of insulin. how is this a clevel cech to also stop secretion

Back 25

secretion stim insulin, insulin then decreases these things in the blood. When the decreased conc is detected insulin secretion is stopped

Front 26

is insulin secretion pulsatile, continuous, ect?

Back 26

Biphasic. Initial spike, late phase gradual increase with plateau

**at first there is a build up of insulin in granules and when blood glucose is high all of the granules are reelased, this causes a SPIKE (increase adn also a decrease)

**after the spike if more insuin is needed it is made denovo and then there is a steady increase in inculin release.

**second phase begins about 10 min after stim and can last for a hours and

Front 27

we know glucose is the major stim for insulin secretion is more insulin released when glucose is oral or IV

Back 27

ORAL

when taken through GI the glucose also stim Glucose dependent insulinotropic peptice (GIP) and GLP1. Both of which independently increase insulin secretion. This gets the body ready for the glucose load that is about to come

**IV GIP and GLP arent sitm

Front 28

when glucose is seen in the GI what other hormones are secreted in order to better accomadate the coming glucose load

Back 28

GIP
GLP

**both stim insulin secretion independtly. THis REALLY amps up the insulin released

Front 29

what does the insulin receptro look like? how does it work

Back 29

a and b sunbunits

a binds insulin
b is the RTK

**when inculin binds to the a subinut the b subunit pi itself. and IRS (insulin receptor substrates) the IRS does its thing and then the receptor is engulfed

Front 30

waht are IRS

Back 30

when insulin binds a subunit or receptor it causes the b subunit to pi itself and IRS

IRS are the tings that cause the physiological response to increase glucose uptake

Front 31

so the insulin can work a few dif ways, whats the normal respone when bound? what about a fast thing? longer? **note these activities are regulated byt he IRS that was Pi by the b subunit

Back 31

Normal: insulin binds and IRS are Pi and cause Glut 4 to be inserted in the membrane

FAST: AA and electrolytes enter through channels

SLow: Lipogenic effects will cause gene expression

Front 32

what does insulin do to glucose metabolism in gthe liver, sk mm, fat

Back 32

increase glucose transport in all 3

**in the liver and sk mm only glycogen synthesis is done

**no glycogen synthesis in the fat

Front 33

what does insulin do to fat metabilism? where are these effects seen?

Back 33

recall inculin acts on the liver, fat, and sk mm

Lipogenesis in the liver and fat
made VLDL and cholesterol in liver

all tissues take up FFA

Front 34

wjat does insulin do to protein metabolism?

Back 34

stim aa uptake and protein synthesis. inhibit protein breakdown ++ N balance

doen in the liver, fat, and sk mm

Front 35

what is the N balance in the presence of insulin

Back 35

positive

Front 36

does insulin work fast? what does it immediatly, after a bit, and more delayed

Back 36

YES!!! within seconds there is in increase in the transport of glucose, aa, and K

within minutes it stim protein and glycogen synthesis

and after hours it stimulates lipogenesis

**the different IRS cause diff things

Front 37

we know inculin is the major product of b cells, what else do b cells secrete

Back 37

1. amylin: decrease glucose uptake un mm and decrease food intake, delay gastric emptying. used to treat DM II

2. Pancreatistatin: autofeedback regulation of inculin release

Front 38

what are amylin nad pancreastatin

Back 38

they are the other products of the b cell (insulin is main)

Amylin: decreases glucose uptake in mm, decrease food intake, delay gastric emptying

Pancreastatin: autofeedback regulation of insulin release

Front 39

does insulin stim the release of FFA

Back 39

nope

Front 40

summary: what 3 tissues doe insulin work on? what stim, inhibits

Back 40

sk mm, liver, fat

Stim by glucose, FFA, AA in blood. inhibited by a decrease in these things int he blood

Front 41

other than metabolism, what else does insulin affect?

Back 41

1. heart: increase CO (+ inotropic effect)
2. thermogensis, get hot after you eat lots
3. increase E expenditure
4. decreases neuropeptide Y to supress appetite
5. increase K reabe

Front 42

what does insulin do to appetite

Back 42

supress it by decreaseing neuropeptide Y

Front 43

what does insulin do to K

Back 43

increase reabs of K and PO4

Front 44

is glycogen a prohormone? is insulin

Back 44

BOTH are

Front 45

where is the proglucoagon hormone made

Back 45

a cells of pancreas
also in intestine

Front 46

what does glucagon do? when is it secreted

Back 46

secreted when blood glucose is low to increase blood sugar levels
**total opposite of insulin, mobilizes fuels rather than storing them

Front 47

so the main insulinogogue was glucose. what is the main glucagonogue

Back 47

hypoglycemia

**low blood sugar causes the release of glucagon which will mobalize sugars from the cells to enter the blood

Front 48

so with insulin it was released whn glucose in blood was high and then inhibited when glucose was low. what is teh pattern for glucagon

Back 48

glucagon causes FFA, ketoacids, and glocose to enter the blood, when these increase in the blood glucagon secretion is inhibited

AA in the blood on the other hand signal to the body that proteins are being broken down adn so will release glucagon so the aa can be converted to sugar

Front 49

aa in the blood do what to glucagon

Back 49

stimulate the release of glucagon! hmm, glucagon then stim the conversion of aa to glucose

Front 50

what does glucagon do to carb metabolism

Back 50

glycogenolysis
gluconeogenesis

Seen in the liver only. glucagon does NOT affect the sk mm

Front 51

does glucagon affect the sk mme?

Back 51

no way jose, only insulin acts on sk mm

Glucogon acts on the fat and liver

Front 52

what does glucagon do to lipid metabolism

Back 52

lipolysis
ketogenesis, make ketone bodies to make glucose

**ketogeneis only occurs in the liver, lipolysis occurs in the liver and fat

Front 53

without insulin what state can we enter

Back 53

acidosis

ketone bodies from ketogenesis

Front 54

what does glucagon do to protein

Back 54

increase aa uptake in the liver for gluconeogenesis

**proteolysis to free aa so they can be used to make glucose

**increases N in the pee - N balance

Front 55

+ N with what hormone
- N with what hormone

Back 55

+ inculin
- glucagon

Front 56

summary of glucagon! wht tissue, what stim, inhibits

Back 56

the liver nad fat

A decrease in plasma glucose leads to gluconeogenesis, glycogenolysis, ketogenesis, and lipolysis to increase plasma glucose, FFA, and ketoacids adn decrease AA

Front 57

when glucagon has been secreted what happens to aa and ketoacids in the blood

Back 57

aa decrease (used to make glucose)

ketoacids increase

Front 58

what does it mean that insulin and glucagon are sounterregulated

Back 58

when plasma glucose increases insulin is secreted and glucagon is inhibited

**if in the other hand plasma glucsose drpos glucagon is stim and insulin is inhibited

Front 59

an increase in what other hormones accompany an increase in glucagon

Back 59

cortisol
GH
Epi

**when plasma glucose drops all of thses will be released

Front 60

so if our plasma glucose levels frop what do we need to do and what hormones do it?

Back 60

get it up!!!
Glucose is preferred fuel for brain so we use glucagon 1st to get glucose

1. EPI
2. GH
3. Cortisol

**we then use thse as back up

Front 61

waht is our back up plan if glucagon isnt working to keep glucse levels in the blood high

Back 61

1. EPI
2. GH
3. Cortisol

Front 62

what is the mormal ration of I to G

Back 62

2

Front 63

what happens to the molar I:G ratio when exercising

Back 63

decreases!
less insuliln is there. We are using our blood sugars so glucagon is released to maintain glucose levels

*aids lipolysis, gluconeogenesis, glycogenolysis

Front 64

what happens to metabolism when the I:G ration is 1

Back 64

LOW, less insulin and more glucagon so increase lipolysis, glycogenolysis, gluconeogenesis

Front 65

what does it mean in your G"I is 10

Back 65

you just had a ton of carbs

**increased insulin secretion to promote uptake and storage of glucose and others

Front 66

what metabolic paths are stim by insulin? glucagon

Back 66

glucose oxidation
glycogen synthesis
protein synthesis
lipogenesis
fed state, promote storage

Glucagon:
lipolysis
gluconeogensis
glycogenolysis
fasted state, promote mobilization

Front 67

a high I:G stim what?
low?

Back 67

High: promotes storage. causes blood to decrease glucose AA FA and ketone bodies

Low: promotes mobilization. Increase Glucose AA FA and ketone bodies in the blood

Front 68

where is somatostatin made? what does it do?

Back 68

delta cells of pancreas
hypothalamus
GI tract

INHIBITS:
insulin
glucagon
GH
GI hormone secreion, motility, papsin, blood flow

Front 69

the role of somatostatin is waht?

Back 69

modulat the resposne of insulin and glucagon to the ingestion of food

Front 70

somatostatin inhibits what hormones

Back 70

insulin
glucagon
GH

**also inhibits GI fx and motility