Chapter 12: WHAT STARTS A MEAL?

Question 1

What hormone is released when the digestive tract is empty? When you’re hungry

Answer 1

ghrelin

Question 2

When do ghrelin increase and decrease?

Answer 2

• increase with fasting
• reduced after a meal
• gastric bypass surgery reduces ghrelin

Question 3

What is the duodenum

Answer 3

• First portion of the small intestine, attached directly to the stomach
• Ghrelin levels decrease when nutrients enter this part of the intestine.

Question 4

What are the main hunger signals?

Answer 4

• depletion of nutrients reservoirs
• hypoglycemia: fall in blood glucose levels
• glucoprivation and lipoprivation

Question 5

What is lipoprivation?

Answer 5

• dramatic fall in the level of fatty acids available to cells
• usually caused by drugs that inhibit fatty acid metabolism

Question 6

Liver detectors?

Answer 6

-conveys signals about gluco and lipoprivation to the brain through the vagus nerve

Question 7

Brain detectors?

Answer 7

• respond to glucoprivation

- in the dorsoventral and ventromedial medulla