Module 8

Question 1

Define Appetite

Answer 1

The desire to eat food

Question 1

The sensation of fullness that leads to the cessation of food intake during a meal is known as ____________.

Answer 1

Satiation

Question 2

Define Hunger. What is the absence of hunger?

Answer 2

1. The physiological drive to consume food
2. Satiety

Question 3

Explain the difference between hunger and appetite.

Answer 3

Hunger is an intervening factor that influences appetite, but there are many other factors that also impact appetite along with hunger.

You can still have an appetite even if you’re not hungry.

Question 4

Where are POMC/CART expressing neurons located in the brain?

Answer 4

Arcuate nucleus of the hypothalamus

Question 5

Stimulation of POMC/CART expressing neurons will result in _______________ (increased/decreased) food intake.

Answer 5

Decreased

Question 6

What part of the brain are NPY neurons and agouti-related peptide (AgRP) located?

Answer 6

Arcuate nucleus of the hypothalamus

Question 7

Stimulation of NPY/AgRP expressing neurons will result in _______________ (increased/decreased) food intake.

Answer 7

Increased

Question 8

What are the 2 ways in which leptin promotes satiety?

Answer 8

Inhibits orexigenic AgRP pathway ⇒ satiety

Stimulates anorexigenic POMC pathway ⇒ satiety

Question 9

Where is Ghrelin secreted from?

Answer 9

The stomach

Question 10

In terms of Satiation and the Role of the vagal afferents, which part of the brain do the vagal afferents synapse onto?

Answer 10

Neurons in the nucleus tract solitarius

Question 11

Explain the process for how CCK affects appetite.

Answer 11

1. When food enters the duodenum, the upper SI cells secrete CCK (Cholecystokinin)
2. CCK binds to CCK1 receptors
3. Activates vagal afferents that end in the nucleus tract solitarius
4. Inhibits the NPY/AgRP pathway
5. Decreases hunger

Question 12

Explain how GLP-1 (glucagon-like peptide 1) affects appetite.

Answer 12

1. Secreted by intestinal cells in response to food intake
2. Binds to receptors in the hypothalamus
3. inhibits NPY/AGrP pathway
4. Decreases hunger

Question 13

How does the microbiome affect appetite regulation?

Answer 13

• SCFA may modulate the secretion of appetite-associated peptides (ex: GLP-1) from enteroendocrine cell
• Metabolites interact with intestinal cells & vagus nerve → (+)/(-) effects on appetite
• Microbial population may affect taste preferences