Pancreas

Question 1

What is the term for islands of endocrine cells within exocrine tissue?

Answer 1

Islets of langerhands

(secrete digestive enzymes)

Question 2

What do the following cells secrete?

𝛃 cells (60% of endocrine cells)

𝛂 cells (25% of endocrine cells)

𝛅 cells

𝛄 cells

𝝐 cells

Answer 2

𝛃 cells = Insulin, Amylin

𝛂 cells = Glucagon

𝛅 cells = Somatostatin

𝛄 cells = Pancreatic polypeptide

𝝐 cells = Ghrelin

Question 3

What hormones inhibit digestive function/ suppress appetite?

Answer 3

Amylin (acts on CNS, suppresses appetite)

Somatostatin (inhibits digestive function)

Pancreatic polypeptide (reduces appetite/ food intake)

Question 4

What is the role of Ghrelin?

Answer 4

Appetite stimulating

Question 5

Preproinsulin is converted to proinsulin which is cleaved in the granules to what?

Answer 5

Insulin + C-peptide (1:1 ratio)

(C-peptide is more reliable measurement for assessing insulin use in DM pts due to longer half life)

Question 6

Glucose stimulates insulin release via what process in beta cells?

Answer 6

Excitation-secretion coupling

Question 7

What is necessary for the facilitated diffusion of glucose across cell membranes?

Answer 7

GLUT2

Question 8

In the process of insulin release, glucose and PO4 yield glucose-6-phosphate which is then oxidized to form what?

Answer 8

ATP

Question 9

What is the role of ATP in the release of insulin?

Answer 9

Closes K+ channels = decreased K+ depolarizes cell membrane

(This leads to voltage- gated Ca channels opening and Ca entering the cell)

Question 10

In the insulin release process, once Ca enters the beta cells, what does this trigger?

Answer 10

Triggers exocytosis of insulin vesicles = insulin secreted into circulation

Question 11

What are the 3 primary effects of insulin?

Answer 11

1. Affect energy stores
2. Recruits GLUT-4 to cell surface
3. Stimulates MAP kinase pathways

Question 12

Excess insulin can lead to hypoglycemia which can then ultimately lead to what?

Answer 12

Depressed brain function/ LOC

Question 13

How does insulin affect energy storage in carbs, lipids, and proteins?

Answer 13

Promotes storage

(decreases blood glucose, fatty acids, and AAs)

Question 14

In what tissues does the insulin dependent transporter GLUT-4 exist?

Answer 14

Adipose and resting muscle cells

Question 15

Where are GLUT 1, 2, and 3 proteins located?

Answer 15

GLUT1 = BBB

GLUT2= kidney/ intestine

GLUT3= neurons

Question 16

How do you treat an insulin OD?

Answer 16

Exogenous sugar

……. or should i say……. a sugary snack

Question 17

How do you treat reactive hypoglycemia (beta cells release too must insulin in response to glucose)?

Answer 17

Control by limit of dietary cards, DO NOT treat with exogenous sugar

Question 18

What is the most common endocrine disorder?

Answer 18

DM = high blood surgar levels over a prolonged period

Question 19

What is the primary difference between T1 and T2 DM?

Answer 19

T1 is autoimmune (T-lymphocytes destroy beta cells = lack of insulin secretion)

T2 is non-insulin dependent (tissue resistant to insulin as a result of life-style choices)

Question 20

What are the acute sxs of DM?

Answer 20

High blood glucose

Question 21

What are the chronic sxs of DM? (4)

Answer 21

Retinopathy, neuropathy, nephropathy, CV disease

Question 22

A value of what on fasting plasma glucose is concerning for DM?

Answer 22

> 126

(N = <110, borderline = 110-125)

Question 23

Ingestion of 75mg of glucose within 5 min and measurement of blood glucose at 60 and 120 min is the protocol for what test?

Answer 23

Oral glucose tolerance test (OGTT)

Question 24

What are considered normal values at 1 and 2 hours of the OGTT?

Answer 24

1 hour < 180

2 hours < 140

Question 25

What is considered DM on a HbA1c test? (average glucose levels over 3 months)

Answer 25

DM **\> 6.5%**

Question 26

What tissues is glucagon expressed in?

Answer 26

Liver, intestine, brain, pancreas

Question 27

Glycogen is converted to glucose via what? (It stimulates gluconeogenesis and glycogenolysis in the liver and lipolysis in adipose tissue)

Answer 27

Glucagon

Question 28

↑ glucose, somatostatin, insulin, fatty acids, keto acids leads to what?

Answer 28

Inhibition of glucagon

Question 29

↓ glucose, epi (𝛃2), vagal stimulation, CCK, fasting, exercise, protein (in the absence of carbs) leads to what?

Answer 29

Stimulation of glucagon

Question 30

Conversion of proglucagon to glucagon also yields what?

Answer 30

Incretin (GLP1)

Question 31

When is GLP1 (incretin) released? And what does its release lead to?

Answer 31

**Increased glucose** levels in **intestinal** lumen Results in increased **insulin release** from beta cells

Question 32

Generally speaking, what is the affect of glucagon on energy stores?

Answer 32

**Favors release** (increased blood glucose, fatty acids/ ketons, and AAs)

Question 33

Glucagon has a minimal effect on what tissue?

Answer 33

**Proteins** (it does increase blood AAs but has minimal effect and **NO effect on skeletal muscle proteins**, which is the major protein storage site)

Question 34

What is the primary affect of somatostatin?

Answer 34

**Inhibits release of insulin and glucagon** (binds to beta and alpha cells via **SSTR2 receptor** and leads to hyperpolarization of cells)

Question 35

Somatostatin release is stimulated by high fat, carbs, and protein. This ultimately leads to what type of effect in the GI tract?

Answer 35

**Inhibitory**; prolonged duration of intestinal food absorption

Question 36

How does somatostatin affect the release of GH?

Answer 36

Inhibits it

Question 37

The CNS plays a role in the control of glucose because it has receptors for nutrient levels and hormones. Where specifically is glucose detected and what hormones does the CNS respond to?

Answer 37

Glucose detection in the **arcuate nucleus** Hormones = **insulin, leptin, GLP1**

Question 38

The hypothalamus regulates glucose homeostasis via insulin secretion but is blocked by what?

Answer 38

Alpha- adrenergic stimulation of SNS

Question 39

What structure regulates the homeostasis of glucose via insulin secretion, glucose secretion, hepatic glucose output, and glucose uptake by skeletal muscles?

Answer 39

Hypothalamus

Question 40

Neural control of glucose involves the control of energy balance via monitoring of what 2 things?

Answer 40

Food intake vs energy expenditure (also control of body weight)

Question 41

What are the orexigenic hormones?

Answer 41

Ghrelin

Question 42

What are the anorexigenic hormones?

Answer 42

Leptin, insulin

Question 43

What hormone favors release of energy stores during short term stress?

Answer 43

Epinephrine

Question 44

What hormone favors release of energy stores during long term stress?

Answer 44

**Cortisol** (decreased glucose uptake in tissues other than the **brain**)

Question 45

Epinephrine results in decreased insulin secretion via what?

Answer 45

Alpha-adrenergic stimulation of beta cells

Question 46

What hormone is released during hypoglycemia, sleep, stress, and exercise, and has a small role in fuel metabolism?

Answer 46

Growth hormone