The endocrine pancreas

Question 1

different islet endocrine cell types

Answer 1

alpha
beta
delta
pp
epsilon

Question 2

what happens when blood glucose is low

Answer 2

beta cells turn off and insulin goes down, glucagon goes up

Question 3

what happens when there is an increase in blood glucose

Answer 3

insulin goes up and glucagon goes down

Question 4

when is the kATP channel open

Answer 4

at low glucose maintaining a hyperpolarised plasma membrane

Question 5

when does the kATP channel close

Answer 5

at high glucose it depolarises the plasma membrane

Question 6

what triggers insulin release

Answer 6

closure of kATP channel

Question 7

role of sulfonylureas

Answer 7

bind the SUR1 subunit of the kATP channel, closing the channel and triggering insulin secretion irrespective of glucose concentrations

Question 8

what else can beta cells sense other than glucose

Answer 8

amino acids
free fatty acids

Question 9

does bet cell failure occur in both types of diabetes

Answer 9

yes

Question 10

what does insulin drive

Answer 10

anabolic pathways in target tissue to promote storage of nutrients and lower blood glucose

Question 11

islet defect in T2DM

Answer 11

impaired insulin secretion
dysregulated glucagon secretion

Question 12

what do alpha cells secrete

Answer 12

glucagon

Question 13

what does glucagon act on

Answer 13

the liver to promote hepatic glucose production , raising blood glucose

Question 14

what does glucagonn contribute to

Answer 14

hyperglycaemia

Question 15

what is somatostatin secreted in response to

Answer 15

nutrient or hormonal stimulation

Question 16

what does somatostatin supress

Answer 16

beta and alpha cell function

Question 17

what does glucagon do once released

Answer 17

informs body to break down triglycerides / glycogen into energy when blood glucose is low

Question 18

effect of alpha cells

Answer 18

increase blood sugar levels

Question 19

where are islet of langerhans

Answer 19

part of body and tail of pancreas

Question 20

where does glucagon travel to

Answer 20

liver, adipose tissue and muscle

Question 21

what does the liver convert glycogen to

Answer 21

glucose

Question 22

what does somatostatin do

Answer 22

inhibits glucagon and insulin , fine tunes

Question 23

how is insulin released

Answer 23

lucose enters beta cell via LGLUT2 transporter where it enters glycolysis and mitochondrial metabolism
Rise in ATP from glycolysis and mitochondrial metabolism
ATP binds to potassium ATP sensitive channel
Rise in ATP causes kATP to close
Closure causes depolarisation of cell membrane depolarisation causes calcium influx via voltage sensitive calcium channel- causing insulin secretion

Question 24

how does glucose enter beta cell

Answer 24

through glut2 transporters

Question 25

what specifically causes the insulin secretion

Answer 25

calcium influx via depolarisation of cell membrane via the katp channel to close