Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

Pathophysiology > L6 > Flashcards

L6 Flashcards

1
Q

Which subunit of the insulin receptor does insulin bind to?
A. alpha
b. beta

A

A. alpha

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

True or False: The alpha subunit of the insulin receptor has tyrosine kinase activity and receptor autophosphorylation

A

False - beta subunit

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

In the insulin receptor, phosphorylation of insulin receptor substrate (IRS) proteins leads to activation of PI3K/MAPk, as well as ___trafficking

A

GLUT-4

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

____: the principal effector of the PI3K pathway

A

AKT

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

True or False: In the insulin receptor, the cytoplasmic protein CBL is the DIRECT phosphorylation target

A

True

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

True or False: Skeletal muscle glucose uptake is increased in T2DM

A

False - skeletal muscle glucose uptake is REDUCED in T2DM

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

Impaired insulin receptor signaling is a result of: ____ cytokines, which is mediated by activation of _____ receptors

A

intracellular; TLR

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

Impaired insulin receptor signaling is a result of: ____ cytokines, which is mediated by ____ (such as: TNF-a)

A

extracellular; adipokines

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

Excessive oxidation of free fatty acids is just one mechanism of skeletal muscle insulin resistance. Which two locations do FFA’s come from?

A

1) Visceral adipose tissue
2) Intracellular lipid storage

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

True or False: Mitochondrial dysfunction and modulation of gene transcription are mechanisms of skeletal muscle insulin resistance

A

True

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

What two sources can activate TLR’s?
A. Bacterial products in plasma (e.g LPS)
B. Antibiotics
C. Cytokines
D. Systemic FFA’s

A

A/D

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

True or False: Obesity alters intestinal bacterial composition

A

True

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

True or False: Leaky gut does NOT allow entry into systemic circulation

A

False - leaky gut ALLOWS entry into systemic circulation

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

Activation of TLR leads to intracellular production of ___ (leads to inflammatory gene expression) and ___

A

NF-kB; MAPK

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

TLR activation generates intracellular cytokines, such as _____

A

TNF-a

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

TLR activation leads to interruption of insulin receptor signaling via: phosphorylation of ____

A

IRS (insulin receptor substrate)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

True or False: Systemic fatty acids activate TLR (e.g TLR4)

A

True

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

Binding of FA to TLR4 leads to activation of ____, which activates NF-kB and MAPK.

A. TNF
B. IL-6
C. proIL-1B
D. MD2
E. MyD88

A

E. MyD88

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

True or False: Activation of NF-kB leads to activation of TNF, IL-6, proIL-1B, and proIL-18

A

True

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

True or False: Bacterial products (LPS) lead to activation of TLR, which leads to production of cytokines and inhibition of insulin signaling

A

True

21
Q

____ KO mice are protected from diet induced obesity (DIO)
A. TLR4
B. MyD88
C. NF-kB
D. MAPK

A

B. MyD88

22
Q

Activation of TLR leads to activation of ___ kinases
A. glutamate
B. glycine
C. serine
D. tryptophan
E. tyrosine

A

C. serine

23
Q

Phosphorylation of serine residues INHIBITS function of insulin receptor and prevents ___ kinase from phosphorylating IRS proteins
A. glutamate
B. glycine
C. serine
D. tryptophan
E. tyrosine

A

E. tyrosine

24
Q

How does TNF-alpha (extracellularcytokine) affect tyrosine kinase activity?

A

Decrease it
- Thereby: block fx of insulin receptor

25
Q

True or False: Visceral adipose tissue has a low lipolytic activity

A

False - it has a HIGH lipolytic activity

26
Q

Insulin resistance ____ lipid accumulation in adipocytes
A. limits
B. exceeds

A

A. limits

27
Q

True or Fales: excess storage capacity of adipocytes (obesity) leads to increased in lipid storage in other organs (e.g - liver, skeletal m., pancreatic islets)

A

True

28
Q

There is a higher density of which type of receptor, in visceral adipose tissue, that contributes to its higher lipolytic activity?

A

High density of adrenergic receptors (B2 on adipocytes is activated by NE/EPI)

29
Q

True or False: In visceral adipose tissue, the isoform of lipase IS effectively inhibited by insulin

A

False - it is NOT

30
Q

Visceral adipose tissue has high ___ activity
A. HSD11B2
B. HSD11B1
C. CYP21

What is the effect?

A

B. HSD11B1 (converts cortisone to cortisol)

  • Leads to increased local cortisol production (lipolysis)
31
Q

How does hormone sensitive lipase (HSL) leads to hyperlipidemia (increased FFA in the blood)?

A

Lipolysis

32
Q

True or False: Unhealthy adipose expansion and inflammation leads to lipotoxicity and ectopic lipid deposition

A

True

33
Q

High: cell hypertrophy, inflammation, macrophage infiltration

Low: adipogenesis and insulin sensitivity

A. Healthy expansion
B. Unhealthy expansion

A

B. Unhealthy expansion

34
Q

How does excessive fatty acyl-CoA beta oxidation affect glycolysis and glucose entry? intermediates?

A

1) Limits it
2) Increased intermediates (e.g DAG, ceramides)

35
Q

Diacylglycerol (DAG) activates ___, which blocks ___ through ____ phosphorylation

A

PKC; IRS-1; serine

36
Q

DAG activates ____, leading to inflammatory response and insulin resistance

A

Diacylglycerol kinase (DGK)

37
Q

Increased fat oxidation in muscle leads to an increased in intermediates, such as: ___

A

DAG

38
Q

What are the four main outcomes of excessive FFA oxidation?

A

1) Excessive generation of fatty acyl CoA
2) Accumulation of DAG
3) Activation of serine kinase (protein kinase C)
4) Serine phosphorylation of IRS proteins

39
Q

What can drive mitochondrial dysfunction?

A

Chronically elevated plasma lipids

40
Q

Dysfunction of which organelle can lead to increased generation of ROS by that very organelle?

A

Mitochondria

41
Q

What are two effects of chronically elevated plasma lipids?

A

1) Make intracellular cytokines via TLR’s
2) Excess FFA B-oxidation

42
Q

True or False: Mitochondrial dysfunction does not harm proteins, lipids, nucleic acids

A

False - mitochondrial dysfunction DOES damage protein, lipids, and nucleic acids

43
Q

How does mitochondrial dysfunction affect:
- # of mitochondria
- mitochondrial function
- oxidative capacity
- GLUT4 transcription

A

Decreases all of the above

44
Q

How can impaired mitochondrial function decreased insulin response?

A

Activates MAPK/NF-kB, increase IRS1 phosphorylation of serine and decrease phosphorylation of tyrosine

45
Q

True or False: When there is impaired mitochondrial function, both increase in FFA derivatives and ROS can lead to activation of MAPK and NF-kB

A

True

46
Q

How does mitochondrial dysfunction affect IRS proteins?

A

Leads to their nitrosylation and degradation

47
Q

What are four characteristics of beta cell dysfunction?

A

1) Altered pattern of insulin secretion
2) Decreased sensitivity to glucose
3) Reduced processing of proinsulin
4) Hyperglycemia induced changes in gene expression

48
Q

True or False: Improved glucose clearance and increased sensitivity to glucose are features of dysfunctional pancreatic beta cel

A

False - IMPAIRED glucose clearance and DECREASED sensitivity to glucose

Pathophysiology (26 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions