Lecture 31 - Feeding and Weight Control Flashcards Preview

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Flashcards in Lecture 31 - Feeding and Weight Control Deck (58)
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1

Peripheral signals involved in weight control
1)
2)
3)

1) CCK
2) Leptin
3) Ghrelin

2

Hypothalamic chemicals involved in weight control
1)
2)
3)

1) Neuropeptide Y
2) POMC
3) Agouti-related peptide

3

Adiposity signals

Leptin
Insulin
Act long-term

4

Peptides that increase food intake
1)
2)
3)
4)
5)
6)

1) Neuropeptide Y
2) Melanin concentrating hormone
3) Agouti-related peptide
4) Orexin A and B
5) Endocannabinoids
6) Ghrelin

5

Peptides that increase food intake that act in the brain
1)
2)
3)
4)
5)

1) Neuropeptide Y
2) Melanin concentrating hormone
3) Agouti-related hormone
4) Orexin A and B
5) Endocannabinoids

6

Peptides that increase food intake that act in the periphery

Ghrelin

7

Peptides that decrease food intake
1)
2)
3)
4)

1) a-melanocyte stimulating hormone
2) CART
3) Leptin
4) Cholecystokinin

8

Peptides that increase food intake that act on the brain

Alpha-melanocyte stimulating hormone

9

Peptides that increase food intake that act in the periphery

CART
Leptin
Cholecystokinin

10

Where is CCK produced, and in response to what?

Produced by gut
Released in response to digestion of certain nutrients, particularly fat

11

What does CCK act on?

Binds to CCKa receptor on vagus nerve.
This transmits information to nucleus tractus solitarius in medulla.
This transmits to hypothalamus to terminate a meal.

12

How does CCK stimulation of vagus nerve affect the brain?

Ascending signal passes through nucleus tractus solitarius to hypothalamus.
Acts on hypothalamus to terminate a meal.

13

Where is ghrelin secreted?

By stomach

14

When do ghrelin levels rise?

Pre-prandially

15

What are ghrelin plasma levels inversely-proportional to?

BMI

16

Effect of increased ghrelin on appetite

Increases appetite

17

Ghrelin receptor name and locaiton

GHSR-1a, located in hypothalamus

18

Effect of increasing CCK level in rats

More frequent, smaller meals. Not much effect on weight.

19

Does ghrelin quickly or slowly modulate hunger?

Quickly

20

What secretes leptin?

Adipocytes

21

What are plasma leptin levels inversely proportional to?

BMI, adiposity

22

Effect of increased leptin on hunger

Decreases hunger

23

How does leptin enter the brain?

Via transporter across the blood brain barrier

24

Parts of hypothalamus that are involved in hunger

Arcurate nucleus
Paraventricular nucleus

25

Arcurate nucleus role in hunger

Contains cell bodies of neurons that project to paraventricular nucleus

26

Hunger-related neurons in arcurate nucleus
1)
2)

1) POMC/CART neurons. When stimulated, reduce food intake
2) Neuropeptide Y/Agouti-related peptide neurons. When stimulated, increase food intake.

27

Neurons that release factors that increase food intake

Neuropeptide Y/Agouti-related peptide neurons in the arcurate nucleus of the hypothalamus

28

Neurons that release factors that decrease food intake

POMC/CART neurons in the arcurate nucleus of the hypothalamus

29

Effect of leptin on the arcurate nucleus

Stimulates POMC/CART neurons, inhibits NPY/AGRP neurons. This results in reduction of food intake.

30

Members of the pancreatic polypeptide family
1)
2)
3)

1) Neuropeptide Y (synthesised in CNS)
2) Peptide YY (GIT)
3) Pancreatic polypeptide (pancreatic islets)