The Endocrine Pancreas - Insulin

Question 1

what peptide hormone suppresses hunger

Answer 1

leptin

Question 2

what two hypothalamic centres control food intake

Answer 2

feeding centre and satiety centre

Question 3

two theories suggest what controls food intake centres . How do they differ

Answer 3

glucostatic theory is blood glucose based whereas lipostatic is fat store based.

Question 4

where is leptin released from

Answer 4

fat stores

Question 5

3 types of energy output

Answer 5

cellular work, mechanical work and heat loss

Question 6

what is the absorptive state

Answer 6

where ingested nutrients supply body energy needs and the excess is stored

Question 7

post-absorptive phase is anabolic/catabolic

Answer 7

catabolic

Question 8

absorptive phase is anabolic/catabolic

Answer 8

anabolic

Question 9

what is the post-absorptive phase

Answer 9

when we break down our body energy stores

Question 10

what sources of energy can the brain use

Answer 10

glucose and ketones

Question 11

in what situation does the brain use ketones for energy

Answer 11

starvation

glycogen release –> fatty acids turned into ketones

Question 12

long term consequence of hypoglycaemia

Answer 12

coma and death

Question 13

in normal metabolism, what happens to excess ingested glucose

Answer 13

it undergoes lipogenesis to fat stores

Question 14

ways that glucose can be made by body

Answer 14

breakdown of glycogen

amino acids into glucose (gluconeogenesis)

Question 15

normal BG level

Answer 15

5mmoles

Question 16

what BG is defined as hypoglycaemic

Answer 16

<3mmoles

Question 17

what BG prick test is defined as hyperglycaemic

Answer 17

> 11mmoles

Question 18

what fasting BG is defined as hyperglycaemic

Answer 18

> 7mmoles

Question 19

two chief hormones of blood glucose control

Answer 19

insulin and glucagon

Question 20

4 types of pancreas cells and what they secrete

Answer 20

alpha - glucagon
beta - insulin
delta - somatostatin
F - pancreatic polypeptide

Question 21

what does pancreatic polypeptide do

Answer 21

we don’t really know, probably helping nutrient absorption

Question 22

trigger of insulin release

Answer 22

blood glucose and amino acid levels increasing

Question 23

what other hormones lower blood glucose

Answer 23

none. only insulin lowers blood glucose

Question 24

what two forms is glucose stored as

Answer 24

glycogen and triacylglycerols

Question 25

where is glycogen stored

Answer 25

in the liver and muscle

Question 26

where is TAG stored

Answer 26

in the liver and adipose tissue

Question 27

mechanism of insulin secretion

Answer 27

glucose --> into cell by GLUT transporter --> metabolism increases --> ATP increases --> Katp channels close --> depolarised --> voltage Ca2+ channels open --> insulin exocytosed

Question 28

what is special about K+ ion channels of B-cells

Answer 28

sensitive to ATP within the cell

Question 29

what channels close in the secretion of insulin

Answer 29

Katp

Question 30

what channels open in the secretion of insulin

Answer 30

Ca2+

Question 31

what does closing Katp channels do to the cells polarity

Answer 31

depolarises it

Question 32

GLUT transporter of glucose into cells of muscle and fat

Answer 32

GLUT-4

Question 33

what receptors does insulin bind to GPCR or tyrosine kinase

Answer 33

tyrosine kinase

Question 34

effect of insulin stimulation of cell

Answer 34

GLUT-4 migrates to cell membrane from cytoplasm and transports glucose

Question 35

what types of tissues need insulin for glucose uptake

Answer 35

muscle and adipose

Question 36

what are the non-insulin dependent tissues

Answer 36

Kidneys, brain, rbc and b-cells of pancreas and liver

Question 37

what GLUT transporter takes up glucose in the liver

Answer 37

GLUT-2

Question 38

how does insulin indirectly effect glucose uptake in liver

Answer 38

insulin release --> hexokinase activated --> converts glucose to glucose 6 in cell--> creates a concentration gradient over membrane --> glucose moves into cell by GLUT-2

Question 39

how does glucose move into liver cells

Answer 39

moves down a concentration gradient

Question 40

effect of insulin on glycogen synthesis

Answer 40

stimulates its synthesis and inhibits its phosphorylase

Question 41

effect of insulin on amino acid uptake

Answer 41

increases it

Question 42

effect of insulin on protein synthesis

Answer 42

increases it and inhibits its lysis

Question 43

effect of insulin on TAG synthesis

Answer 43

increases

Question 44

effect of insulin on gluconeogenesis

Answer 44

inhibits enzymes of gluconeogenesis

Question 45

effect of insulin on K+ ions

Answer 45

promotes entry into cells by stimulating Na+/K+ ATPase

Question 46

where is insulin degraded

Answer 46

mostly liver and kidneys

Question 47

what happens to insulin bound receptors after

Answer 47

they are ENDOcytosed and destroyed. | some are recycled

Question 48

stimuli of insulin release

Answer 48

increased BG and aa. glucagon (to take up the glucose that glucagon causes to be made) vagal nerve activity GI secretory and motility hormones

Question 49

inhibitor of insulin release

Answer 49

low BG. somatostatin stress sympathetic alpha2 effects?

Question 50

what has greater effect on insulin secretion. intravenous or oral delivery of glucose

Answer 50

oral. because vagus nerve is stimulated to release GI hormones and insulin in addition to the B-cells being directly stimulated