[3] Pancreas

Question 1

Normal # of Islets of Langerhans

Answer 1

1,000,000

Question 2

Diameter of an Islet

Answer 2

0.2mm

Question 3

Weight of a Thyroid

Answer 3

25g

Question 4

Weight of the Pituitary Gland

Answer 4

500-600mg

Question 5

Weight of the Endocrine Pancreas

Answer 5

1.0-1.5g

Question 6

4 Cell Types of Islets of Langerhans

Answer 6

A
B
D
F

Question 7

What do A cells secrete?

Answer 7

Glucagon; 20% of cells

Question 8

What do B cells secrete?

Answer 8

Insulin; 60% of cells

Question 9

What do D cells secrete?

Answer 9

Somatostatin

Question 10

What do F cells secrete?

Answer 10

Pancreatic Polypeptide

Question 11

Describe the alpha and beta components of an Insulin Receptor

Answer 11

A: Extracellular Domain
B: Transmembrane Domain

Question 12

What type of a receptor is an Insulin Receptor?

Answer 12

Receptor Tyrosine Kinase

Question 13

2 instances where there is increased glucose uptake by skeletal muscles

Answer 13

During exercise

After a meal under the influence of insulin

Question 14

Which glucose transporter is Insulin-Dependent?

Answer 14

GLUT4

Question 15

Main Glucose Transporter found in B Cells

Answer 15

GLUT2

Question 16

Function of GLUT2

Answer 16

B Cell Glucose Sensor

Question 17

Glucose Transporters of the Brain

Answer 17

GLUT1

GLUT3

Question 18

3 Types of Ketone Bodies (Formed during starvation)

Answer 18

B-Hydroxybutyrate
Acetoacetate
Acetone

Question 19

Important Role of Calcium in Insulin Release

Answer 19

Depolarization causes opening of Ca2+ channels and the increased concentration causes the release of Insulin

Question 20

[Effect on Insulin Secretion]

B-Adrenergic Stimulation
A-Adrenergic Stimulation

Answer 20

B: Increase (Beta-as)
A: Decrease (Alpha-ba)

Question 21

Explain: The Incretin Effect

Answer 21

Differences in taking glucose orally or intravenously

People who take glucose orally had plasma glucose similar to those who took it intravenously, BUT when it comes to insulin secretion those who took it orally had a much greater insulin secretion than the intravenous one

Question 22

Define: Incretins

Answer 22

Intestinal factors that increase secretion of insulin in response to oral glucose intake

Question 23

2 Types of Incretin

Answer 23

GIP: Glucose-Dependent Insulinotropic Peptide

GLP-1: Glucagon-like Peptide-1

Question 24

What produces GIP Incretins?

Answer 24

K Cells of the Duodenum and Proximal Jejunum

Question 25

What produces GLP-1 Incretins?

Answer 25

L Cells of the Distal Ileum and Colon

Question 26

How long will it take for an IV Infusion of Glucagon to deplete the liver of its total glycogen stores?

Answer 26

4 Hours

Question 27

What is the most important factor that regulates glucagon secretion?

Answer 27

Glucose

Question 28

Effect of Increased Amino Acids on Insulin and Glucagon

Answer 28

Increases the secretion for both of them

Question 29

Why is there a need to tightly control glucose levels?

Answer 29

1. Glucose is the only fuel used by the brain, retina, and germinal epithelium of the gonads
2. High glucose levels can cause cellular dehydration
3. High glucose levels can cause osmotic diuresis and promote loss of electrolytes
4. Chronically high levels of glucose cause endothelial damage and atherosclerosis, leading to target organ damage

Question 30

4 Factors that Increase Glucose Levels

Answer 30

Glucagon
GH
Cortisol
CCK