normal endo pancreas 1

Question 2

Islets of LangerhansSympathetic adrenergic input(______-nerve – from coeliac plexus)Parasympathetic, cholinergic input(___nerve)

Answer 2

1. Splanchnic 2. Vagus

Question 3

in ER, proinsulin is exposed to ______ excise C peptide, –> mature insulin. Insulin + C peptide packaged in Golgi into secretory granules : accumulate in the ___-.

Answer 3

1. endopeptidases2.cytoplasm

Question 4

What stimulates insulin secretion? (6)

Answer 4

• ↑ [ glucose ]• ↑ [ free aa ]• ↑ [ GI hormones ] (gastrin, secretin, CCK, GIP) • ↑ [ glucagon ]• Noradrenaline (low conc; α- receptors)• Acetylcholine

Question 5

What inhibits insulin secretion? (4)

Answer 5

• Decreased [ glucose ]• ↑ [ somatostatin ] • Noradrenaline (high conc; β-adrenergic ) • Adrenaline (β-adrenergic )

Question 6

What stimulates glucagon secretion? (3)inhibits? (1)

Answer 6

• Decreased [ glucose ]• ↑ [ free aa ]• Adrenaline• Increased [ glucose ]

Question 7

What stimulates somatostatin? (4)

Answer 7

• Carbohydrates• Proteins• Fats• Decreased pH in duodenum

Question 8

Insulin-Mediated Glucose Disposal (IMGD)• 85% of IMGD –> ______and _________

Answer 8

skeletal muscle + adipose tissue

Question 9

GLUT4 (major t/p in muscle) Absence of insulin : •GLUT4 stored in ______ Insulin–> Fusion vesicles and insertion glucose transporters in ________

Answer 9

cytoplasmic vesiclesplasma membraneGLUT4:high affinity, insulin responsive

Question 10

Effects of insulin on liver•Activates hexokinase –>____glucose (traps it in cell)•Activates glycogen synthesis enzymes e.g. _____and glycogen synthase•Inhibits activity of __________

Answer 10

phosphorylates phosphofructokinase glucose-6-phosphatase

Question 11

Glycogen Synthase (GS)& Glycogen Phosphorylase (GP)PKA phosphorylates and activates PKB,which activates _____PKA phoshorylates and inactivates ___,:prevents cycling of glucose-1-P–>

Answer 11

Glycogen PhosphorylaseGlycogen Synthaseleads to Glycogen breakdown

Question 12

Glucagon switches ___Glycogen Phosphorylase• Glucagon activates AC–> cAMP–>______ –> phosphorylase kinase—> GP GPb —> GPa

Answer 12

ON cAMP-dependent kinase (PKA)

Question 13

Glucagon switches ____GS Glucagon activates PKA –> _____(hence inactivates) GS activates ____  Inhibits _____ Prevents dephosphorylation (hence reactivation) of ___________

Answer 13

OFF Phosphorylates glycogen phosphorylasephosphoprotein phosphataseglycogen synthetase

Question 14

Insulin switches ON ____ ______ Insulin activates phosphoprotein phosphatase ________ glycogen synthetase Insulin inhibits cAMP-INdependent kinase Prevents____ (hence inactivation) of GS

Answer 14

glycogen synthetaseDephosphorylates phosphorylation

Question 15

Insulin - ANABOLIC↑ net TAG synthesis:Activates __________Inactivates ___________

Answer 15

acteyl-CoA carboxylasehormone-sensitive lipase (HSL)

Question 16

Glucagon – CATABOLICStimulates net breakdown of TAG (spares glucose)Inactivates________Activates_________

Answer 16

acteyl-CoA carboxylase hormone-sensitive lipase (HSL)

Question 17

Glucose metabolism linked to Lipogenesis•Pyruvate enters TCA – citrate can exit for___•Glycolysis generates α-phospho-glycerate : backbone of __•Pentose phosphate pathway generates reduced ______

Answer 17

Fatty acid synthesisTAGcofactors for FA biosynthesis

Question 18

Glucagon switches __acetyl-CoA carboxylase Glucagon activates PKA  ___ a-CoA carboxylase also activates ___  Inhibits _____ ____ Prevents _____(hence reactivation) of a-CoA carboxylase

Answer 18

OFF Phosphorylates glycogen phosphorylasephosphoprotein phosphatasedephosphorylation

Question 19

Insulin switches __acetyl-CoA carboxylase Insulin activates phosphoprotein phosphatase _______a-CoA carboxylase Insulin __cAMP-independent kinase Prevents _____ of acetyl-CoA carboxylase

Answer 19

ON Dephosphorylatesinhibitsphosphorylation

Question 20

Hormone-sensitive lipase and futile cycling HSL catalyses rds in fat metabolism (TAG–> DAG +NEFA) ___stimulates FAS, so inhibits TAG metabolism to ___ Insulin ____HSL

Answer 20

Insulinprevent futile cycling inhibits

Question 21

Hormone-sensitive lipase and futile cycling Glucagon stimulates fat catabolism to spare glucose / promote ____ Glucagon activates PKA  ___HSL To spare glucose, ___increase fat metabolism by up-regulating expression of HSL.

Answer 21

gluconeogenesis Phosphorylates glucocorticoids

Question 22

What % of pancreas is:exocrine (lobules)?ducts? endocrine (Islets of Langerhans) ?

Answer 22

1. 80%2. 4%3. 2%