The endocrine pancreas 1 and 2

Question 1

2 ‘theories’ (pathways) that control energy intake etc

Answer 1

glucostatic theory

lipostatic theory

Question 2

glucostatic theory

Answer 2

food intake is determined by blood glucose

Question 3

lipostatic theory

Answer 3

food intake is determined by fat stores (as fat stores increase, drive to eat decreases)

Question 4

3 categories of energy output

Answer 4

cellular work

mechanical work

heat loss

Question 5

anabolic pathways

Answer 5

build up

net effect is synthesis of large molecules from smaller ones, usually for storage purposes

Question 6

catabolic pathways

Answer 6

break down

net effect is degradation of large molecules into smaller ones, releasing energy for work

Question 7

after eating, we enter the ……. state where ingested nutrients supply energy needs of the body and excess is stored

this is the ………. phase

Answer 7

absorptive

anabolic

Question 8

between meals and overnight the pool of nutrients in the plasma decreases and we enter a …………. state where we rely on body stores to provide energy

this is the ……. phase

Answer 8

post-absorptive

catabolic

Question 9

most cells can use fats, carbohydrates or protein for energy, but the brain can only use

Answer 9

glucose

except in extreme starvation

Question 10

blood glucose is maintained by synthesising glucose from ……….. (………….) or amino acids (…………..)

Answer 10

glycogen

(glycogenolysis)

(gluconeogenesis)

Question 11

what is the normal range of blood glucose?

Answer 11

4.2-6.3mM

Question 12

hypoglycaemia occurs when blood glucose is less than what?

Answer 12

3mM

Question 13

glucose is maintained over a tight range due to the actions of two key endocrine hormones produced in the pancreas:

Answer 13

insulin

glucagon

Question 14

99% of the pancreas operates as an ……. gland

Answer 14

exocrine

Question 15

only 1% of the pancreas has ……… function

Answer 15

endocrine

Question 16

alpha cells produce

Answer 16

glucagon

Question 17

beta cells produce

Answer 17

insulin

Question 18

gamma cells produce

Answer 18

somatostatin

Question 19

F cells produce

Answer 19

pancreatic polypeptide

Question 20

insulin is synthesised as a large preprohormone called

Answer 20

preproinsulin

Question 21

preproinsulin gets converted into ……… in the ………

Answer 21

proinsulin

ER

Question 22

proinsulin is cleaved into ……. and ………..

Answer 22

insulin

c-peptide

Question 23

Most cells use glucose as their energy source during the absorptive state. Any excess is stored as ………….. in liver and muscle, and as ………… in liver and adipose tissue.

Answer 23

glycogen

triacylglycerols (TAG)

Question 24

fatty acids are stored in the form of triglycerides in ……. ……. and the ……….

Answer 24

adipose tissue

liver

Question 25

the liver takes up glucose by ……… transporters, which are ………. dependent

Answer 25

GLUT2

insulin

Question 26

insulin increases ……..synthesis in muscle and liver

Answer 26

glycogen

Question 27

insulin increases …… ……. uptake into muscle

Answer 27

amino acid

Question 28

4 main stimuli that inhibit insulin release

Answer 28

low BG

somatostatin

sympathetic alpha effects

stress (eg hypoxia)

Question 29

vagal activity increases or decreases insulin release?

Answer 29

increases

Question 30

what kind of hormone is glucagon?

Answer 30

peptide

Question 31

glucagon has a plasma half life of 5-10minutes and is degraded mainly by the….

Answer 31

liver

Question 32

the primary function of glucagon

Answer 32

to raise blood glucose

it is a mobilising hormone

Question 33

what hormone primarily opposes the actions of insulin?

Answer 33

glucagon

Question 34

glucagon is most active in which state?

Answer 34

post-absorptive

Question 35

Glucagon receptors are G-protein coupled receptors linked to the adenylate cyclase/cAMP system which when activated phosphorylate specific liver enzymes resulting in:

3.

Answer 35

increased glycogenolysis

increased gluconeogenesis

formation of ketones from fatty acids

Question 36

Glucagon release is relatively constant although secretion increases dramatically when [BG] < …….. mM

Answer 36

5.6

Question 37

normal blood glucose in mM is between ……. and ……….

Answer 37

4.2 - 6.3 mM

Question 38

What are also a potent stimulus for glucagon secretion?

Answer 38

amino acids

Question 39

5 main stimulti that promote glucagon release

Answer 39

low BG

high AA

sympathetic innervation (epinephrine)

cortisol

stress (exercise, infection)

Question 40

4 stimuli that inhibit glucagon release

Answer 40

glucose

free fatty acids and ketones

insulin

somatostatin

Question 41

increased parasympathetic activity (vagus) leads to …….. insulin and to a lesser extent ……… glucagon, in association with the anticipatory phase of digestion.

Answer 41

increased

increased

Question 42

increased sympathetic activation promotes glucose mobilization leads to …….. glucagon, ……… epinephrine and INHIBITION of insulin, all appropriate for fight or flight response.

Answer 42

increased

increased

Question 43

somatostatin is secreted by what type of cells?

and also the ……

Answer 43

D cells

hypothalamus

Question 44

somatomedian C is also known as

Answer 44

IGF-1

Question 45

the main PANCREATIC action of somatostatin is to …

Answer 45

inhibit activity in the GI tract

slows down the absorption of nutrients

Question 46

somatostatin is NOT a counter-regulatory hormone in the control of blood glucose but it does strongly suppresses the release of both ……. and ………. in a paracrine fashion.

Answer 46

insulin

glucagon

Question 47

in the loss of control of BG in diabetes - patients will produce large volumes of what?

Answer 47

sweet tasting urine

Question 48

type 1 diabetes is the autoimmune destruction of the pancreatic beta cells which destroys their ability to produce ……. and seriously compromises patients ability to absorb …. from the plasma

Answer 48

insulin

glucose

Question 49

ketoacidosis in diabetes

When nutrients are scarce, body relies on stores for energy – when adipose tissue is broken down …… …….. are released. FFA’s can be readily used by most tissues to produce energy and liver will convert excess to ……. …….. which provides an additional source for muscle and brain!

Answer 49

fatty acids

ketone bodies

Question 50

ketoacidosis in diabetes:

in poorly controlled insulin-dependent diabetes a lack of insulin depresses ….. …… uptake. They build up rapidly in the plasma and because they are acidic create life threatening acidosis (ketoacidosis or ketosis) with plasma pH < 7.1. Death will occur within hours if untreated.

Answer 50

ketone body

Question 51

what is the first line of treatment for T2DM?

Answer 51

metformin

Question 52

what does metformin do?

Answer 52

inhibits hepatic gluconeogenesis and antagonises action of glucagon

Question 53

Sulphonylureas are a class of drug which act to

Answer 53

close the KATP in beta cells and therefore stimulate Ca2+ entry and insulin secretion.

Question 54

Patient ingests glucose load after fasting [BG] measured. [BG] will normally return to fasting levels within an hour, elevation after 2 hours is indicative of …..

Answer 54

diabetes

Question 55

the entry of insulin into …… …….. is increased during exercise

Answer 55

skeletal muscle

Question 56

exercise increases the ……. ……. of muscle and causes an insulin-independent increased in …….. ……… incorporated into the muscles membrane

Answer 56

insulin sensitivity

GLUT4 transporters

Question 57

when adipose tissues are broken down - what is released?

Answer 57

fatty acids