Exam 5: The Endocrine Pancreas and Carbohydrate Metabolism Flashcards Preview

Physiology > Exam 5: The Endocrine Pancreas and Carbohydrate Metabolism > Flashcards

Flashcards in Exam 5: The Endocrine Pancreas and Carbohydrate Metabolism Deck (32)
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1
Q

How is GLUT4 regulated?

A

Insulin

2
Q

Where is a GLUT4 transporter not located?

A

Brain

Liver

3
Q

How does insulin circulate?

A

Mostly unbound

4
Q

What are the functions of insulin?

A

Anabolic
Decrease blood glucose
Facilitates tissue uptake of glucose, amino acids, fatty acids, K, Mg, and P
Stimulates glycogen synthesis, lipogenesis, protein synthesis and storage
Inhibits glycogenolysis, lipolysis, and protein catabolism

5
Q

What does insulin receptor binding do?

A

Activates some intracellular enzymes and inactivates others

6
Q

How quickly does the 1st insulin receptor binding result?

A

Within seconds

7
Q

What happens after the 1st insulin receptor binding?

A

80% of body’s cells increase glucose uptake (muscle, adipose, not most neurons)
Immediate phosphorylation of glucose

8
Q

Where is insulin not required the most for glucose transport?

A

Neurons

9
Q

What are additional insulin binding effects?

A

Increase cell membrane permeability to amino acids, K, and P
Intracellular flow, so it will decrease blood concentration
Slower insulin effect, 10-15 min, which will increase or decrease activity level of many intracellular enymes

10
Q

What does muscle do in the presence of insulin?

A

Absorbs glucose for immediate energy

Synthesizes glycogen for use later

11
Q

What does the liver do in the presence of insulin?

A

Stimulates glycogenesis

Inhibits glycogenolysis

12
Q

What does insulin on liver CHOs promote?

A

Glucose storage in the form of glycogen

13
Q

What happens when insulin enhances the liver’s glucose uptake and retention?

A

Increase activity of glucokinase

Decrease activity of phosphatase

14
Q

What happens when insulin activates glycogen synthesis enzymes?

A

Increase glycogen synthase

15
Q

What happens when insulin inhibits the breakdown of glycogen?

A

Decrease activity of liver phosphorylase

16
Q

What happens to the liver in the absence of insulin?

A

Releases glucose into the circulating blood

17
Q

What happens with the promotion of fat synthesis and storage by insulin?

A

Carbohydrate excess (promotion of fatty acid synthesis in hepatocytes)
Promotes FA transport to and storage in adipose tissue
Inhibits lipolysis

18
Q

What does lipoprotien lipase (activated by insulin and FA) allow?

A

Storage of TG in adipose tissue

19
Q

What occurs with lipid and insulin deficiency?

A

Lipolysis

Ketone formation in liver

20
Q

What does insulin promote for protein?

A

Protein synthesis and storage

21
Q

What does the promotion of protein synthesis and storage by insulin do?

A

Stimulates transport of amino acids into cells, including muscle
Inhibits protein catabolism
Decrease hepatic gluconeogenesis

22
Q

What does the stimulation of transport of amino acids do?

A

Increase translation of mRNA

23
Q

What is the primary regulator of insulin release?

A

Blood glucose

24
Q

How does glucose enter β cells?

A

GLUT-2

25
Q

What is glucose proportional to?

A

Blood glucose concentration

26
Q

What does the rate of glucose entry control?

A

Excytosis of insulin vesicles

27
Q

What does high BG do to insulin secretion?

A

Increases it

28
Q

What does low BG do to insulin secretion?

A

Decreases it

29
Q

What are the functions of glucagon?

A
Anti-insulin/diabetogenic
Rapid acting
Hepatic glycogenolysis
Hepatic gluconeogenesis
Lipolysis
30
Q

What does decreased glucose do to glucagon secretion?

A

Increases it

31
Q

What does increased glucose do to glucagon secretion?

A

Decreases it

32
Q

What do amino acids do in glucagon regulation?

A

Stimulate glucagon secretion

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