Chapter 10- Control of Feed Intake (Nov 29)

Question 1

a combination of ___ contribute to long-term control of feed intake
eg.

Answer 1

signals

• leptin, ghrelin

Question 2

lipostatic control theory of feed intake states

Answer 2

animals eat to maintain set lipid reserves

Question 3

seasonal effects of feed intake are regulated in part by the ___ ___

Answer 3

pineal gland

- reacts to day length by receiving light cues)

Question 4

in bears, how does the pineal gland play a role?

Answer 4

plays a part in getting the animal to consume a lot of food before hibernating

Question 5

what are the 4 gastrointestinal chemical receptors?

Answer 5

1. receptor in gut for fat and protein
2. receptors for blood glucose level
3. osmotic pressure- presence of solutes in the intestinal lumen causes influx of water
4. stretch receptors - physical limitations to intake

Question 6

what do the gastrointestinal chemical receptors for blood glucose level do when:

a) blood glucose decreases
b) blood glucose increases

Answer 6

a) blood glucose decreases= glucagon released –> increases blood glucose
b) blood glucose increases= insulin released –> needs for cells to take up the glucose

Question 7

what is the name of the receptor in the gut for fat and protein?

what does it do?

Answer 7

Cholecystokinin (CCK)
= released in response to fat and protein in the small intestine
- stimulated digestion of fat and protein –> release of bile and enzymes

• CCK is a hunger suppressant (effect not immediate)

Question 8

hormonal control of insulin

Answer 8

reduces food intake (anorexia)
- causes uptake of glucose by cells

• reduced insulin sensitivity= obesity, diabetes

Question 9

what’s the most important hormone regulating energy balance?

Answer 9

leptin

Question 10

hormonal control of leptin

Answer 10

• feedback regulation
• adipocytes release leptin –> reduces feed intake
• in circulation in proportion to body fat

Question 11

the counterpart to leptin is ____

Answer 11

ghrelin

Question 12

hormonal control of ghrelin

Answer 12

• increases food intake/ fat storage
• released by the stomach
• activated NPY neurons

Question 13

control of feed intake is ultimately under control of the ___

Answer 13

brain

Question 14

what is neuropeptide Y?

Answer 14

• a neurotransmitter
• secreted by hypothalamus
• stimulates food intake
• decreases physical activity

Question 15

ventromedial nucleus=

Answer 15

the part of the hypothalamus that influences the animal to stop eating

• satiety center

Question 16

lateral nucleus=

Answer 16

the part of the hypothalamus that influences the animal to start eating.

• hunger center

Question 17

animals have specific ____ for:

Answer 17

appetites (= nutritional “wisdom”)

• salt
• some amino acids?
• non-nutreitns?

Question 18

what is an example of an animal having a specific appetite for a non-nutrient

Answer 18

macaw birds eating clay

- the clay binds toxins so they can eat more things

Question 19

within the range where an animal can compensate, energy intake remains relatively ___

Answer 19

constant