GI 4

Question 1

Satiety definition

Answer 1

The feeling of fulfillment or satisfaction

Question 2

The hypothalamus is important to regulate which 3 things?

Answer 2

Metabolic rate
Food intake
Body weight

Question 3

Satiety center

Answer 3

Ventromedial hypothalamus

Lesions here cause hyperphagia, and animals become obese

Question 4

Hunger center

Answer 4

Lateral hypothalamus

Lesions here cause aphagia, and animal refuse to eat

Question 5

Arcuate nucleus

Answer 5

Part of the hypothalamus

Contains an appetite control circuit governed by hormones

Question 6

2 main types of neurons in the arcuate nucleus

Answer 6

NPY expressing ones (increase food intake)

POMC/CART expressing ones (decrease food intake)

Question 7

Which peripheral hormone is the only one that increases appetite?

Answer 7

Ghrelin

Question 8

4 most important satiety signals

Answer 8

Cholecystokinin
Glucagon, GLP-1
Peptide YY (3-36)
Ghrelin

Question 9

2 ways satiety signals can act

Answer 9

Through the circulation, through the BBB, and to the hypothalamus
Activate the vagus nerve which then signals the hypothalamus

Question 10

Peptide YY

Answer 10

Released by L cells of the small intestine (same as ones that release GLP-1)
Deficiency in PYY is in obesity - increases the chance of being obese
Reduces caloric intake
Acts both directly at hypothalamus and through vagus nerve

Question 11

Glucagon-like peptide-1

Answer 11

Released by L cells of the small intestine (incretin)
Enhances glucose-induced stimulation of insulin synthesis
Suppresses glucagon secretion
Delays gastric emptying
Used for treatment of diabetes (maybe obesity too)

Question 12

CCK in appetite

Answer 12

Binds to specific receptors on vagal sensory terminals that lead to a sense of fullness
Infusion reduces the size of meals and decreases post-prandial hunger in humans

Question 13

3 functions of ghrelin

Answer 13

Increases GH secretion
Increases during fasting, decreases after a meal
Increased levels produce increased appetite

Question 14

Ghrelin in obese people

Answer 14

Have low baseline levels

Levels do no drop after a meal

Question 15

Leptin

Answer 15

Released by adipocytes
Circulating levels correlate with fat stores
Receptors are abundant on neurons in the arcuate nucleus
Levels increase after a meal/overfeeding
Giving leptin decreases food intake, increases energy expenditure, and results in weight loss

Question 16

2 key problems with hormones in obesity

Answer 16

Insulin resistance

Leptin resistance

Question 17

Gastric leptin vs adipose leptin

Answer 17

Gastric has same effect, but short term

Question 18

BMI

Answer 18

Weight (kg) divided by height^2

Question 19

Main 3 complications of obesity

Answer 19

Diabetes
Hypertension
Dyslipidemia

Question 20

4 things that contribute to obesity

Answer 20

Physical activity
Food intake
Monogenic syndromes
Susceptibility genes

Question 21

4 general ways obesity can be treated pharmacologically

Answer 21

Inhibit absorption
Appetite reduction
Satiety enhancement
Increase metabolic rate