endocrine pancreas

Question 1

what is the endocrine portion of the pancreas made up of ?

Answer 1

islets of langerhans

Question 2

what are the cell types in the islets of langerhans?

Answer 2

beta cells - insulin
alpha cells - glucagon
delta cells

Question 3

what is the precursor of insulin ?

Answer 3

preproinsulin
cleaved into c peptide and into insulin

Question 4

what gated receptor is associated with the entry of glucose into the cell ?

Answer 4

GLUT 2

Question 5

what is the first enzyme for glycolysis ?

Answer 5

glucokinase

Question 6

what is insulin release inhibited by?

Answer 6

epinephrine
due to alpha 2 receptor activation
which in turn in creases the plasma glucose levels

Question 7

what type of transporter is GLUT-2 ?

Answer 7

bidirectional transporter

Question 8

what enzyme facilitates the conversion of glucose into glucose 6 phosphate ?

Answer 8

glucokinase

Question 9

what channels are associated with insulin release ?

Answer 9

voltage gated calcium channels open

Question 10

what is activated once insulin is bound to insulin receptors ?

Answer 10

activation of tyrosine kinase domains

Question 11

what is the cascade that happens upon binding of insulin to its receptor ?

Answer 11

tyrosine kinase activation
this leads to autophosphrylation
this leads to the activation of the PIK3 pathway
this allows for th expression of the GLUT 4 receptor

Question 12

what is the function of the RAS/MAP kinase system ?

Answer 12

modify cell growth and gene expression

Question 13

what are the insulin dependant organs ?

Answer 13

muscles and fats

Question 14

what are the insulin independent organs ?

Answer 14

Brain and the RBC
use the GLUT-1

Question 15

what are the effects of insulin ?

Answer 15

increases glycogen synthesis
inhibits glucogenesis
increases fatty acid synthesis
increases protein synthesis

Question 16

what is a key side effect of insulin therapy ?

Answer 16

weight gain

Question 17

what is hormone sensitive lipase inhibited by ?

Answer 17

insulin

Question 18

what is hormone sensitive lipase activated by ?

Answer 18

glucagon and epinephrine

Question 19

what is the effect of insulin on electrolytes ?

Answer 19

sodium retention
lowers potassium

Question 20

what is the treatment for life threatening hyperkalemia ?

Answer 20

insulin plus glucose

Question 21

what is the main stimulus for glucagon release ?

Answer 21

low glucose levels

Question 22

how can we tell if insulin is endogenous or exogenous ?

Answer 22

measure c peptide levels

Question 23

what does high insulin levels in the blood present as ?

Answer 23

presents as whipples triad
1) hypoglycemia
2) symptoms of hypoglycemia
3) worsens between meals
gets better with meals

Question 24

how does glucagon increase blood glucose levels ?

Answer 24

by glucogenesis

Question 25

what processes are increased by glucagon ?

Answer 25

glucogenesis

Question 26

what are the processes increased by glucagon ?

Answer 26

glucogenesis glycogenolysis lipolysis protein catabolism

Question 27

how does insulin promote protein synthesis ?

Answer 27

allows for an anabolic state by decreasing ubiquitin mediated proteolysis

Question 28

how does glucagon activate lipolysis ?

Answer 28

via hormone sensitive lipase

Question 29

what type of protein receptor is associated with glucagon and what is the associated cascade of events ?

Answer 29

G protein recepto activates adenyly cyclase increases cAMP activates protein kinase A PKA

Question 30

where are glucagon receptors mainly found ?

Answer 30

mostly in the liver

Question 31

what are the treatment option for a patient with hypoglycemia who is unconscious ?

Answer 31

IV dextrose or intramuscular glucagon

Question 32

what is the treatment for beta bloker overdose and what is the mechanism ?

Answer 32

glucagon activated adenyl cyclase raises cAMP

Question 33

what is an insulinoma ?

Answer 33

pancreatic islet cell tumor fasting hypoglycemia insulin is high even when fasting

Question 34

what are the symptoms of insulinoma ?

Answer 34

neurologic symptoms sympathetic activation from low glucose

Question 35

how is a diagnosis of insulinoma made ?

Answer 35

fasting insulin level is high c peptide is elevated proinsulin is high

Question 36

what are the differentials of fasting hypoglycemia ?

Answer 36

exogenous insulin oral hypoglycemics insulinoma

Question 37

what is the presentation of glucagonoma ?

Answer 37

glucose intolerance presents like diabetes

Question 38

what are the classic features of glucagonoma ?

Answer 38

necrolytic migratory erythema genitlas buttocks and groin

Question 39

what is the treatment for glucagonoma ?

Answer 39

somatostatin analog

Question 40

what are the different MEN syndromes ?

Answer 40

MEN 1 - pituitary adenoma , parathyroid adenoma and pancreatic cancer MEN 2A - parathyroid adenoma, pheochromocytoma, medullary thyroid carcinoma MEN 2B - Marfanoid body habitus, mucosal neuroma, pheochromocytoma , medullary thyroid carcinoma

Question 41

what are the gene mutations associated with each type of MEN ?

Answer 41

MEN 1 - MEn 1 gene mutation MEN 2A and 2B both have RET gene mutation

Question 42

what is the classic presentation associated with MEN 1 ?

Answer 42

patient with recurrent gastric ulcers complaining of flank pain flank pain - calcium urolithiasis zollinger ellison syndrome - gastrinoma

Question 43

what is carney complex ?

Answer 43

a group of tumors hyperpigmemtation around the mucosa atrial myxoma endocrine hyper secretion in the form of cushing or hyperthyroidism

Question 44

influx of what type of electrolyte is associated with insulin release ?

Answer 44

calcium