Pancreatic Hormones

Question 1

Beta cells, alpha cells, and delta cells secrete _

Answer 1

Insulin
Glucagon
Somatostatin

Question 2

What is the significance of the portal system connecting the liver and pancreas?

Answer 2

Hormones from the pancreas reach the liver in very high concentrations

Question 3

Insulin is secreted directly into the blood. What are the precursors? What else is contained in the insulin secretory granules

Answer 3

Pre-pro
Pro-
insulin + C peptide

Question 4

Insulin is composed of 2 AA chain joined by _ bonds

Answer 4

Disulfide

Question 5

Maximal insulin effects require binding to 90% of available insulin receptors. true or false?

Answer 5

False. Only 10% binding required

Question 6

The insulin receptor is a tetramer. What subunit and domain binds insulin? What is transmembrane?

Answer 6

Alpha - cysteine rich domain

Beta

Question 7

Insulin receptor activation leads to increased conversion of glucose to glycogen. What is the only glucose transporter that is responsive to insulin?

Answer 7

GLUT 4 - upregulated following receptor activation

Question 8

The 2 immediate results of insulin receptor activation are _

Answer 8

Increase glucose transport into cell

Increase AA and ion influx for protein synthesis

Question 9

What are the effects of insulin on liver phosphorylase and liker glucokinase?

Answer 9

Inhibits phosphorylase (breaks down glycogen)
Promotes glucokinase (traps glucose)

Question 10

Brain cells depend on insulin for glucose up take. True or false?

Answer 10

False. Brain cells are glucose permeable without insulin i.e. they don’t need Glut4

Question 11

The major function of insulin is to use up glucose as only energy source, while blocking use of fats or glycogen.

Answer 11

Just know this

Question 12

Type 1 diabetics have elevated levels of plasma cholesterol and FAs. WHy?

Answer 12

Because the absence of insulin promotes hepatic breakdown of free FAs to phospholipids and cholesterol

Question 13

Ketoacidosis occurs in diabetics because _

Answer 13

Excess acetoacetic acid is formed from liver

Question 14

How does insulin interact with GH?

Answer 14

Synergizes to promote growth

Question 15

In beta cells, glucose enters via _. How does this affect ADP levels? What does this accomplish?

Answer 15

GLut2
Increased ADP / reduced ATP
Closing ATP sensitive ion channels
Depolarization, Ca++ influx, Insulin release

Question 16

The major effects of glucagon are _ (2)

Answer 16

Increased glycogenolysis

Increased gluconeogenesis

Question 17

Glucagon increases insulin release. True or false? What hormone depresses both glucagon and insulin release?

Answer 17

True

Somatostatin

Question 18

Type 1 diabetes can be caused by viral infection. true or false?

Answer 18

True. Hereditary suceptibility to beta-cell destruction

Question 19

What is metabolic syndrome?

Answer 19

obesity, insulin resistance, hypertension, hyperglycemia and elevated plasma lipid, all precursor for diabetes and cardiovascular disease

Question 20

Thyroid hormone and Cortisol are hunger (promoting / depressing)

Answer 20

Promoting

Question 21

Leptin, Insulin, CRH are hunger (promoting / depressing)

Answer 21

Depressing

Question 22

A proposed link between obesity and diabetes is that in the obese state, there is increased expression of _ in the mitochondria

Answer 22

Uncoupling protein 2

Question 23

Hyperinsulinism is characterized by shock due to too low insulin levels. This can be treated by _

Answer 23

Surgery

Diazoxide (reduces insulin release)