Endocrine Physiology I

Question 1

What are the two functions of the pancreatic cells?

Answer 1

1. Make enzymes
2. Make hormones (Endocrine)

Question 2

What are the main function of Acini (cluster of cells)?

Answer 2

Make enzymes that dump into the duodenum via pancreatic duct

Question 3

Where are the majority of hormones created in the pancreatic cells?

Answer 3

Islet of Langerhans
-Glucagon, insulin, and somatostatin

Question 4

In the pancreas, what do alpha cells (20%) make?

Answer 4

Glucagon

Question 5

In the pancreas, what do beta cells (70%) make?

Answer 5

Insulin

Question 6

In the pancreas, what do δ cells (10%) make?

Answer 6

Somatostatin

Question 7

What is the function of somatostatin?

Answer 7

Inhibits Insulin, Glucagon and GH

Question 8

What is the normal range of glucose (mg/dl)?

Answer 8

~80-100 mg/dL

Question 9

How does insulin and glucagon balance each other?

Answer 9

Question 10

What effect does amino acids have on glucagon and insulin?

Answer 10

Same, slightly positive effect

Question 11

What has the greatest effect on the release of insulin?

Answer 11

Hyperglycemia

Question 12

What has the second greatest effect on insulin release?

Answer 12

Incretins (GIP/GLP)

Question 13

What has a moderate postive effect on insulin release? (2)

Answer 13

Glucagon, Sulfonylurea drugs

Question 14

What has an inhibitory effect on insulin? (3)

Answer 14

NE/Epi & Cortisol, Somatostatin, Fasting/excersize

Question 15

What has the greatest effect of the release of glucagon? (1)

Answer 15

Hypoglycemia

Question 16

What has a moderate positive effect on the release of glucagon? (3)

Answer 16

Amino acids, NE/Epi & Cortisol, Excersize/fasting

Question 17

What has a moderete negative effect on the release of glucagon? (3)

Answer 17

Incretins (GIP/GLP), Insulin, Somatostatin

Question 18

What do sulfonylurea drugs do? (3)

Answer 18

They stimulate insulin release

• Treat T2D
• Block B-Cell K_ATP

Question 19

B-Cells release what? (2)

Answer 19

Insulin and C-peptide (Connecting-peptide)

Question 20

What do incretins do?

Answer 20

Incretins stimulate the B-cells and inhibit the alpha cells to increase insulin and lower glucagon.

Question 21

What does the enzyme dipeptidyl pedptidase-4 (DPP4) do?

Answer 21

Inactivate GLP-1 and GIP

Question 22

What do antagonists of DPP-4 do?

Answer 22

Antagonists of DPP-4 improve endogenous insulin secretion!

Question 23

Is insulin release higher when glucose is given orally or through IV?

Answer 23

Orally

Question 24

What function does insulin have on glucose and AA uptake in skeletal muscle?

Answer 24

Anabolic

• Increases glucose and AA uptake in skeletal muscle
• Supresses hepatic glucose production
• Inhibits lipolysis​

Question 25

What effect does glucagon have in liver, adipocytes and skeletal muscle? (4)

Answer 25

**Catabolic** - Increases hepatic glycogenolysis - Increeases hepatic gluconeogenesis - Increases hepatic ketone formation - Stimulates lipolysis

Question 26

What is the largest storage site of glucose, and the tissue responsible for T2D?

Answer 26

Skeletal muscle

Question 27

What receptor does insulin act on in myocytes/adipocytes?

Answer 27

GLUT4

Question 28

What pathway mediates most of insulin's metabolic effects? The phosphorylation of what proteins mediates this pathway?

Answer 28

Akt pathway IRS-1, Akt, PKCz, AS160

Question 29

What is insulitis?

Answer 29

Question 30

What is the cause of type 1 diabetes?

Answer 30

Loss of beta cells by autoimmune destruction, usually genetic and triggered from environmental factors. This ultimately leads to low insulin levels and decreased glucose uptake that leads to hyperglycemia

Question 31

In T1D, as beta cell mass decreases, what happens to insulin release over time?

Answer 31

Question 32

What leads to the development of type 2 diabetes (T2D)?

Answer 32

Insulin resistance from inactivity and genetics precedes obesity. Obesity leads to B-cell hyperplasia where glucose is normal and insulin is elevated. In early B-cell fatigue, glucose and insulin are elevated. In late B-cell failure, glucose is elevated and insulin is decreased.

Question 33

What causes insulin resistance?

Answer 33

Excess glucose intake leads to oxidative stress where a JNK protein phosphorylates a serine residue on IRS-1, inactivating the Akt pathway that normally brings GLUT4 receptors to the membrane to uptake glucose

Question 34

If you wanted to transport glucose at the same rate of an insulin sensitive person, and you were insulin resistant how would you achieve normoglycemia?

Answer 34

You would have to produce more insulin, which is what happens in early stages of type 2 diabetes

Question 35

What effect does T2D's have on endogenous glucose production and glucose disposal rate? (2)

Answer 35

Question 36

Preoperative elevated HBA1C is a predictor of what?

Answer 36

Question 37

What clinical implications does diabetes have regarding anesthesic management?

Answer 37

Question 38

Low insulin/glucagon can lead too? (Primarily in T1D)

Answer 38

Ketogenesis, elevated sugar, dehydration, and coma

Question 39

What is the best clinical indicator that a patient has insulin resistance?

Answer 39

Obesity

Question 40

High fructose corn syrup ultimately leads to increase of?

Answer 40

VLDL

Question 41

What functions as a glucose sensor in the process of insulin release?

Answer 41

Pancreatic B-cell

Question 42

The IRS-PI3K pathway is essential for glucose uptake by ________ and \_\_\_\_\_\_\_\_\_?

Answer 42

insulin and exercise

Question 43

What are the principle metabolic effects of insulin? (3)

Answer 43

1. Increase glucose utilization in skeletal muscle 2. Supress hepatic glucose production 3. Inhibit lipolysis

Question 44

What do incretins do?

Answer 44

Amplify glucose-induced insulin release

Question 45

How does glucagon antagonize insulin's effects?

Answer 45

Stimulating hepatic glucose release

Question 46

What does a disruption in the balance of insulin and glucagon lead too? (2)

Answer 46

1. Ketogenesis 2. Hyperosmolar coma

Question 47

T or F. Your body metabolizes fructose much differently than glucose?

Answer 47

True

Question 48

What is the main function of the hypothalamus?

Answer 48

Question 49

What is the main function of the pituitary?

Answer 49

Question 50

Where are the magnocellular neurons located in the pituitary? What are there function?

Answer 50

Posterior Produces OT, AVP and stores

Question 51

Where are the parvicellular neurons stored? What are their function?

Answer 51

Anterior Produces releasing/inhibiting hormones

Question 52

What are the neurohormones (releasing hormones)?

Answer 52

Question 53

What are the tropic hormones?

Answer 53

Question 54

What are the non-tropic hormones?

Answer 54

Question 55

How is GH (Somatotropin) release regulated?

Answer 55

Question 56

What are the normal biological actions of GH-IGF-1?

Answer 56

Decrease glucose uptake Increase lipolysis Increase hepatic gluconeogenesis Decrease skeletal muscle glucose uptake Increase lean body mass Increase organ size Increase linear growth

Question 57

Why is GH release pulsatile, rather than sustained?

Answer 57

Question 58

Why is GH surge at night significant?

Answer 58

Growth and repair during rest

Question 59

What effect would a high carbohydrate meal before bed have?

Answer 59

Question 60

How does thyroid hormone, growth hormone, androgens and estrogens vary over time in a normal person?

Answer 60

Question 61

What are the net effects of GH/IGF-1 on growth?

Answer 61

Question 62

What disease is GH overexpression before puberty?

Answer 62

Question 63

What disease is GH deficiency before puberty?

Answer 63

Question 64

What is achondroplasia?

Answer 64

Mutation in gene 3 (FGFR3); not related to GH

Question 65

What is acromegaly?

Answer 65

GH overexpression that starts at puberty and sustains through adulthood

Question 66

What is Laron's syndrome?

Answer 66

GHR insensitivity; no IGF1