endocrine pancreas and glucose regulation

Question 1

functional anatomy of the pancreas

Answer 1

98% exocrine
-digestive enzymes and bicarbonate
-secreted thru pancreating duct

2% endocrine
-peptide hormones regulating glucose and other intermediary metabolism
-secreted by exocytosis- drains into hepatic portal vein

Question 2

what are the exocrine cells of the pancreas

Answer 2

duct and acinar cells
-NaHCO3 and digestive enzymes

Question 3

what cells are the endocrine portion of the pancreas

Answer 3

islets of langerham

Question 4

hormones secreted by islet cells

Answer 4

B/ beta cells secrete insulin and amylin
A/ alpha cells secrete glucagon
D cells secrete somatostatin GHIH
PP cells secrete pancreatic polypeptide

Question 5

role of insulin

Answer 5

stimulate uptake and storage of energy substrates

Question 6

role of glucagon

Answer 6

stimulates production of glucose by liver- gluconeogenesis

Question 7

somatostatin role

Answer 7

general inhibition of exocrine and endocrine pancreatic secretion/ acts in paracrine fashion

Question 8

panceatic polypeptide role

Answer 8

inhibition of exocrine pancreatic secretion

Question 9

what is the role of pancreatic hormones

Question 10

what is the role of pancreatic hormones

Answer 10

provide constant supply of glucose to CNS

Question 11

what do pancreatic hormones respond to

Answer 11

feasting and fasting

Question 12

when does the absorptive or fed state occur

Answer 12

first hours after eating

Question 13

when does the postabsorptive or fasted state occur

Answer 13

between meals

Question 14

what is the most significant regulated variablee

Answer 14

blood glucose concentration

Question 15

what does excessive glucose in the brain do

Answer 15

has detrimental effects long term due to inapproperiate glycosylation reactions

Question 16

what controls insulin and glucagon secretion

Answer 16

blood glucose concentration

Question 17

what hormone is dominant in the fed state

Answer 17

insulin

Question 18

what does insulin do

Answer 18

cellular uptake of nutrients
carb and fat storage
protein anabolism

Question 19

what does glucagon do

Answer 19

catabolism
breakdown of fat, car, and protein

Question 20

when is glucagon dominant

Answer 20

in the fasted state

Question 21

what are some factors that affect insulin secretion

Answer 21

high aa level

glucose entry in small intestine stimulating
-GIP- gastric inhibitory peptide/ glucose dependent insulinotropic peptide
-GLP1- glucagon like peptide 1

higher parasympathetic activity- innervation of beta cells

Question 22

what accomplishes passive facilitated diffusion of glucose across cellular membranes

Answer 22

GLUTs 1-6

Question 23

what GLUTs are alwyas present in their respective cell membranes and what is this called

Answer 23

all but 4
limited tissue distribution

Question 24

where does glut 1 transport glucose

Answer 24

across BBB

Question 25

GLUT 4

Answer 25

insulin depepndent transporter that is recruited to membrane upon insulin binding to its receptor--- reversible process

Question 26

where does GLUT4 transport glucsoe

Answer 26

skeletal muscle and adipose

Question 27

is insulin needed for glucose uptake in exercising muscle

Answer 27

no muscle contraction caues insertion of GLUT 4 into cell membranes

Question 28

what does the brain and liver not need for glucose uptake

Answer 28

insulin

Question 29

what does chronically high insulin level lead to

Answer 29

down regulated receptors

Question 30

what decreases affinity of receptors

Answer 30

excess glucocorticoids- stress response

Question 31

what upregulates insulin receptors

Answer 31

starvation

Question 32

what increases affinity of insulin receptors

Answer 32

chronically low insulin levels or adrenal gland insufficiency

Question 33

major effects of insulin on carbohydrate metabolism

Answer 33

decreases blood glucose and increases carb storage

Question 34

major effects of insulin on carbohydrate metabolism detail

Answer 34

inc glycogenesis in skeletal muscle and liver dec in hepatic glucogoneogenesis inc in glucose uptake by fat cells and resting skeletal muscle

Question 35

how do atheletes abuse insulin

Answer 35

inject insulin and then eat high sugar good attemtping to increase glycogen storage in skeletal muscle

Question 36

what is the risk of injecting insulin

Answer 36

hypoglycemia and coma bc they get the fast acting insulin

Question 37

synthetic insulin allowance

Answer 37

it is banned for atheletes and is sensed by sensitive assays

Question 38

insulin effect on fat metabolism

Answer 38

decreaes bloody fatty acids and inc triglyceride storage inc transport of fa into fat cells inc triglyceride synth by increasing glycose transport into gat cells activates enzymes that catalyze synth of fa from glucose inhibits lipolysis

Question 39

insulin effect on protein metabolism

Answer 39

dec blood AA and inc protein synthesis inc transport of blood AA into muscle and other cells inc protein synth inhibits protein degradation

Question 40

what are some other factors influencing insulin secretion

Answer 40

inhibition of insulin by somatostatin- paracrine from D cells -inc sympathetic activity -during exercise or acute stress -ensures glucose supply to brain and active muscle

Question 41

primary control of glucagon secretion

Answer 41

negative feedback bw alpha cells and blood glucose concentratino -dec in blood glucose inc glucagon secretion

Question 42

what are some factors that increase secretion of glucagon

Answer 42

sympathetic activity inc in AA counteracts insulin effect and prevents hypoglycemia after high protein low carb meal

Question 43

effect of glucagon on fat and carb metabolism

Answer 43

opposite of insulin inc blood glucose by inc liver gluconeogenesis and glycogenolysis inc blood FA and ketone bodies by increasing production in liver and fat -inc lipolysis and metabolism of FA to ketone bodies -dec triglyceride synthesis

Question 44

glucagon relatino to hypo and hypersecretion of pancreatic hormones

Answer 44

no known assocaited with glucagon hypersecretion of insulin- hypoglycemia

Question 45

hypoglycemia

Answer 45

beta cell tumor overdose of insulin in diabetics CNS effects- sweating, palor, inc heart rate, anxiety, confusion, convulsions, coma

Question 46

diabetes mellitus

Answer 46

undesecretion or resistance of insulin- HYPERGLYCEMIA

Question 47

what does high glucose do to blood vessels

Answer 47

damages them by glycosylation reactions neuropathy, nephropathy, cardiovascular disease

Question 48

how many diabetics are type 1

Answer 48

10%- IDDM

Question 49

how many diabetics are type 2

Answer 49

90% NIDDM- non insuolin dependant

Question 50

how is diabetes mellitus diagnosed

Answer 50

glucose tolerance test

Question 51

type 1 diabetes

Answer 51

autoimmune destruction of beta cells insulin dependant daily insulin injections