Neural + Hormonal Mechanisms in the control of EATING BEHAVIOURS

Question 1

2 types of biological mechanisms

Answer 1

1)Neural
2)Hormonal mechanisms

Question 2

hunger

Satiation

Answer 2

signalling for a need for nutrients and the energy they provide

Signalling the satisfaction of these needs

Question 3

Neural mechanisms theory

Answer 3

-THe brain s involved in monitoring and controlling the internal environment

Specifically the hypothalamus

The hypothalamus regulates blood glucose levels

Explained by the Dual centre (control) model

Question 4

the Dual centre (control) model

Answer 4

2 structures provide homeostasis control :

-Lateral Hypothalamus switches on eating (the feeding centre)

-Ventro-medial hypothalamus -switches off eating (the satiety centre)

Question 5

On the whole, the neural mechanisms theory in the control of eating behaviour states that…

Answer 5

eating behaviour is controlled by the hypothalamus (neural mechanisms)

Question 6

Homeostasis to STOP eating:

Answer 6

-Optimum blood glucose levels
-Rise in blood glucose levels
-Ventro-medial hypothalamus detects change
-Feelings of satiation
-STOP eating
-Dall in blood glucose levels
-Optimum blood glucose levels

Question 7

Homeostatis to TRIGGER eating

Answer 7

-Optimum blood glucose levels
-Drop in blood glucose levels
-Lateral hypothalamus detects change
-Feelings of hunger
-Eating
Glucose levels ris e
-optimum glucose levels

Question 8

How does Ghrelin work in control of eating behaviour

Answer 8

1)Ghrelin is a hormone secreted by the stomach
3)It is a hormonal marker of how long since we’ve last eaten
3)The amount produced is related to how empty the stomach is
4)Ghrelin levels are detected by a part of the hypothalamus called the arcuate nucleus
5)When Ghrelin rises above a set point, the arcuate nucleus sends signals to the LH
6)The LH secretes neuropeptide Y
7) NPY stimulates hunger

Question 9

How does Leptin work in control of eating behaviour

Answer 9

1)Leptin is a hormone produced by adipose (fat) cells
2)It acts as an appetite suppressant and contributes to the VMH satiety mechanism
3)Levels of leptin in the blood increase with fat cells
4)This increases is dete4cted by the VMH
5)IF levels increase beyond a certain point, the individual feels full and stops eating

Question 10

Research into hormonal control of eating behaviours

Answer 10

Wren et al (2001)​

• Gave participants Ghrelin intravenously​
• It caused a short-term increase in amount of food eaten​

Licinio et al (2004)​

Studied people with an extremely rare genetic condition where leptin cannot be produced​

Leptin-replacement therapy​

FOUND:​

Average weight loss of more than 40%​

Reduction in food intake of 49%​