Endocrine Pancreas: Insulin and Glucagon Flashcards Preview

Endocrinology > Endocrine Pancreas: Insulin and Glucagon > Flashcards

Flashcards in Endocrine Pancreas: Insulin and Glucagon Deck (32):
1

The Islets of Langerhans in the pancreas contain what cell types

Alpha, Beta, Delta, F cells

2

Alpha cells in the islets do what?

Glucagon synthesis

3

Beta cells in the islets do what?

Insulin Production

4

Delta cells in the islets do what?

Somatostatin

5

F cells in the islets produce what?

Pancreatic polypeptide

6

Where do the alpha cells tend to be located within the islet?

The outside of the cell

7

Where do the beta cells tend to be located within the islet?

The inside of the cell. Delta cells tend to be in between

8

What does somatostatin do in the pancreas?

We know that somatostatin is an inhibitory hormone. It inhibits insulin and glucagon production in the pancreas. Works in a paracrine fashione

9

Insulin synthesis

Proinsulin --> insulin + C peptide

10

B cells make highly electron dense granules

KNOW

11

Know that insulin and C- peptide are both packaged into granules and that they are both dumped out in equal molar amounts

truth.

This can sometimes be important clinically. For example, if you have a pt who is insulin dependent but may have some residual B cell function and you want to know how much...you can measure C-Peptide level

12

Major stimuli for insulin secretion?

Increase in Plasma glucose
Increase in plasma amino acids
Increase in GI hormones

Increase in Parasympathetic NS (Ach)---Better absorption (insulin) when you aren't stressed
Decrease in sympathetic

13

Major stimuli for glucagon relase

Decrease in plasma glucose
Increase in plasma amino acids- (If you eat a steak with no bread, so high protein with no carbs, your amino acid levels will rise which will stimulate insulin release and your glucose will plummet. The release of GLucagon prevents sudden hypoglycemia

14

Do you see changes in peripheral glucagon levels after a big meal?

NO!!! It mostly goes to the liver.
KNOW

15

Insulin release occurs in what pattern?

Rapid oscillations

16

Insulin half life?

about 5 minutes

17

Glucagon half life?

5-10

18

Most of insulin degradation occurs where?

Kidney and liver

19

Glucagon degradation occurs where

most occurs in the liver

20

KNOW! Both hormones, insulin and glucagon, first go to the liver. Large amounts of each are extracted by the liver and exert their actions there. Much of these secreted hormones is also degraded by the liver so it never gets out to the rest of the body

ok

21

Whereas Glucagon's major target tissue far and away is the liver, the major target tissues for insulin are:

Muscle, Liver, Adipose (three largest tissue sin the body)

22

KNOW: What tissues does insulin not stimulte glucose uptake

Brain
Intestinal mucosa
Red Blood Cells
Kidney Tubules

23

What is the main role of glucagon

Promotes glucose release from the liver- to maintain normal plasma glucose conc

24

Hepatic actions of glucagon are?

Glycogenolysis inc
Increase in amino acid uptake
Increase in gluconeogenesis
Increase in ketoneogenesis

25

Glucagon and catecholamines need prior action of what to function optimally in the liver?

Cortisol

26

What are some important enzymes altered by Glucagon?

-Inc in phosphorylase activity
- decrease in glycogen synthetase activity

27

Insulin is the most potent storage hormone

ok

28

Major role of insulin>

Promotes the synthesis of each of the three main nutrient storage forms: Protein, carbs, fats

29

Look at the major actions of insulin

ok

30

What are the effects of Growth hormone on onsulin release and sensitivity of target tissues

Increases insulin release but decreases the sensitivity of target tissue

31

What are the effects of cortisol on insulin release and sensitivity of target tissues

Increases insulin release but decreases sensitivity

32

What are the effects of T3 on insulin release and sensitivity of target tissue

T3 increases insulin release and increases sensitivity of target tissues.