Insulin

Question 1

what percentage of the pancreas is ‘endocrine’?

Answer 1

1%

Question 2

what are the patches of endocrine pancreas tissue known as?

Answer 2

islets of langerhans

Question 3

what are the 4 types of islet cells?

Answer 3

alpha, beta, delta and F

Question 4

what do alpha islet cells produce?

Answer 4

glucagon

Question 5

what do beta islet cells produce?

Answer 5

insulin

Question 6

what do delta islet cells produce?

Answer 6

somatostatin

Question 7

what is somatostatin also known as?

Answer 7

growth hormone inhibiting hormone

Question 8

what do F islet cells produce?

Answer 8

pancreatic polypeptide

Question 9

is insulin a peptide, amine or steroid hormone?

Answer 9

peptide

Question 10

which pancreatic cells produce insulin?

Answer 10

beta islet cells

Question 11

what form is insulin first synthesised in?

Answer 11

preproinsulin

Question 12

where is preproinsulin converted?

Answer 12

ER

Question 13

what is preproinsulin converted to?

Answer 13

proinsulin

Question 14

where is proinsulin converted?

Answer 14

within granules in secretory vesicles

Question 15

what is proinsulin converted to?

Answer 15

insulin and C-peptide

Question 16

what is the major stimulus for insulin secretion?

Answer 16

blood glucose concentration

Question 17

insulin is the only hormone which ____________

Answer 17

insulin is the only hormone which lowers [BG]

Question 18

which receptors does insulin bind to on the target cells?

Answer 18

tyrosine kinase receptors

Question 19

what effect does insulin binding to tyrosine kinase receptors have?

Answer 19

increases glucose uptake by those cells

Question 20

which glucose transporter does insulin mobilise in muscle and adipose tissue?

Answer 20

GLUT-4

Question 21

which types of tissue are insulin dependent?

Answer 21

muscle and fat

Question 22

where can GLUT-1 transporters be found?

Answer 22

brain, kidney, red blood cells, among others

Question 23

which glucose transporters do beta cells in the pancreas use?

Answer 23

GLUT-2

Question 24

is the liver insulin dependent?

Answer 24

no

Question 25

is the insulin response to an intravenous glucose load more or less than the equivalent amount of glucose administered orally, and why?

Answer 25

less - orally administered glucose increases insulin production by direct effect on beta cells AND vagal stimulation of beta cells, plus incretin effects

Question 26

which hormone primarily opposes the action of insulin?

Answer 26

glucagon

Question 27

where does glucagon mainly act?

Answer 27

liver