Fuel Supply Regulation Flashcards Preview

► Med - Year 1 > Fuel Supply Regulation > Flashcards

Flashcards in Fuel Supply Regulation Deck (50)
Loading flashcards...
1
Q

nutrient depletion sensors (2)

A
  • AMP kinase

- sirtuins

2
Q

adequate nutrient availability sensor

A

mTOR system

3
Q

Cellular stress and excess nutrient sensor

A

UPR system

4
Q

Central integrator of nutrient balance location

A

medial-basal hypothalamus

5
Q

Signals that indicate adequate nutrient stores (4)

A
  • leptin
  • CCK
  • GLP-1
  • serotonin
6
Q

Signals that indicate nutrient depletion (2)

A
  • Ghrelin

- Neuropeptide Y

7
Q

alpha MSH neuronal pathways importance

A

regulation of hypothalamic output –neuronal and endocrine–ensures energy balance

8
Q

The regulation of food intake is not adequate to ensure energy homeostasis. What fine-tunes the energy homesotatic balance? How?

A

Energy–alters the efficiency of fuel and ATP use!

9
Q

The efficacy of the hypothalamic energy homeostatic control system can be overridden by what type of pathways?

A

cortical (especially limbic)

-many are related to the function of the dopaminergic reward system

10
Q

What do AMP kinases sense?

A

inadequate intracellular energy stores, sensing the intracellular AMP/ATP ratio

11
Q

When activates, the AMP kinases promote

A

catabolic pathways

12
Q

Sirtuin system are what type of proteins? What is their function?

A

deacetylases, regulating protein function and synthesis in response to intracellular energy stores

13
Q

When activates, the mTOR complex initiates types of reactions that lead to what?

A

cellular growth and proliferation

14
Q

What does the mTOR complex inhibit?

A

Autophagy

15
Q

What inhibits the mTOR complex?

A

Activated AMP kinase

16
Q

mTOR complexes are an intermediate step in ______

A

signal transduction for growth factors

17
Q

AMP kinase indirectly stimulates ___ by inhibiting mTORc

A

autophagy

18
Q

What causes unfolded proteins and thus the unfolded protein response? (UPR)

A

excessive intracellular stores result in synthesis of underglycosylated proteins; undergo inappropriate folding

19
Q

The UPR process includes

A
  • protein synthesis reduction
  • additional protein glycosylation
  • synthesis of chaperones
  • targets defective proteins toward the proteasomal pathway
20
Q

One consequence of UPR

A

increased lipid synthesis and build up of intracellular TGs

21
Q

Besides intracellular glucose and fatty acids, what other events can trigger UPR?

A

Hypoxia, increased ROS, viral infection, etc.

22
Q

In terms of energy homeostasis what determines the size of the energy reservoir?

A
  • caloric intake
  • efficiency of calorie digestion and absorption
  • caloric usage
23
Q

CNS centers that sense and modulate the size of the energy reservoir. What do they do? Which is the most important feeding/satiety center?

A
  • dorsal brainstem “feeding center” – NTS, vagal motor nucleus–initiation of feeding programs in response to signals from GI tract and optimize digestion and absorption
  • parabrachial nucleus –important in aversion training
  • amygdala–taste inputs, feeling of satisfaction and reward, drive for feeding behavior

-hypothalamus is the most important feeding/satiety center

24
Q

Principal integrator for all the sensory info regarding the status of energy reservoir and coordinates appropriate output signals to maintain optimal energy reservoir size

A

hypothalamus

25
Q

Destruction of the medial/basal hypothalamic area causes, among other symptoms, _____

A

morbid obesity (result in excessive food intake and decreased energy use)

26
Q

The hypothalamus contains a complex neuronal system to integrate multi-sensory inputs. There are important components to help regulate output signals to make sure energy stores are at set point. List the 4

A
  • leptin receptors
  • MSH receptor (MCR4)
  • endocannabinoid receptors
  • CART–protein stimulate by cocaine and amphetamine
27
Q

An important neurotransmitter involved in regulation of energy balance (modulates response to energy sensors at all levels of energy balance hierarchy)

A

Serotonin

28
Q

Serotonin/NE reuptake inhibitors have a tendency to (increase/decrease) body weight

A

decrease

29
Q

Master switch for regulation of energy balance

A

basal and lateral hypothalamus

30
Q

This signal senses the size of the lipid store

A

Leptin from adipose tissue

31
Q

anorexigenic

A

fullness

32
Q

orexigenic

A

emptiness

33
Q

CCK, enterostatin, and GLP-1 are (anorexigenic/orexigenic)

A

anorexigenic (fullness)

34
Q

Ghrelin signals (anorexigenic/orexigenic)

A

orexigenic

35
Q

A few functions of leptin (4)

A

signals adequate fat stores to various tissues (negative insulin secretion)
+ steroid synthesis
+angiogenesis
+CD4+ and CD8+ Tcells and APCs to stimulate humoral and cell-mediated adaptive immunity

36
Q

alpha-MSH

A

inhibits food intake and stimulates ATP use via binding to an MCR4 receptor

37
Q

leptin inhibits food intake by stimulating what system?

A

alpha-MSH system

38
Q

serotonin

A

inhibits food intake, stimulates ATP use

39
Q

CART

A

catecholamin-amphetamine regulated transcript –inhibits food intake and stimulates ATP use

40
Q

endocannabinoids

A

stimulate food intake, conserve ATP

41
Q

individuals with a leptin or leptin receptor defect become

A

morbidly obese

42
Q

Polymorphisms in what two molecules might cause resistance to diet induced weight loss

A

leptin or leptin receptor defects, or UCP proteins

43
Q

Agonists of ___ can be used to promot appetite

A

cannabinoid (important for individuals on chemotherapy and who suffer from various chronic disorders)

44
Q

Can individuals with leptin receptor defects profit from administration of alpha-MSH?

A

Yes, this bypasses the need for the leptin receptor in the hypothalamus!

45
Q

Amphetamines (adderall) and cocaine have what effect on appetite?

A

Suppressors. Not acceptable for weight reduction use due to marked side effects

46
Q

efficiency of energy use by all cells is roughly estimated using

A

BMR

47
Q

SIRT1 activates ___ and AMPK activates ____

A

AMPK, and SIRT1

48
Q

The 4 pathways for energy store regulation are functionally intertwined and insure proper energy balance in each cell. If this fails, what happens?

A

Cell targeted for apoptosis

49
Q

3 important orexins

A

NPY, AGRP, cannabinoids

50
Q

3 important anroxexins

A

serotonin, catecholamines, alpha-MSH