Evaluation of neural and hormonal mechanisms

Question 1

Limitations of a homeostatic explanation

Answer 1

For hunger to be adaptive must be anticipating and preventing energy deficits not just react to them- has not evolved (explain what it does e.g. prevents once falls below)

Question 2

Problems with the role of the lateral hypothalamus- damage and behavior

Answer 2

Damage to LH causes issues in other areas of behaviour e.g. thirst and sex not just hunger

Question 3

Problems with the role of the lateral hypothalamus- recent research

Answer 3

Recent research eating behaviour controlled by neural circuits which run throughout the brain, not just hypothalamus

Question 4

Problems with the role of the lateral hypothalamus- sakurai et al

Answer 4

Plays in part of role but not brain’s eating centre

Question 5

Support for the role of the ventromedial hypothalamus- early researchers found

Answer 5

damage/ lesions to VMH resulted in hyperphagia and obesisty in different species in humans

Question 6

Support for the role of the ventromedial hypothalamus- gold designated VMH as what?

Answer 6

Satiety centre in eating behaviour with PVN important role

Question 7

Support for the role of the ventromedial hypothalamus- most studies found

Answer 7

when compared to lesions in other brain areas, animals with VMH lesions ate a lot more and gained more weight as a result

Question 8

Support for the role of the ventromedial hypothalamus- counter argue .. other research

Answer 8

However other research suggest it is a particular area of CMH not just VMH (PVN)

Question 9

Research support for the role of ghrelin - Wren et al study did what?

Answer 9

repeated method- support role of ghrelin in appetite control in randomised double blind study of 9 volunteers (healthy ones)

Question 10

Research support for the role of ghrelin - Wren et al study participants received what?

Answer 10

Either- received intravenous ghrelin (salive is control and is the exp group) or saline infusions
- 1 week later same participants did other condition

Question 11

Research support for the role of ghrelin - Wren et al found and states

Answer 11

increase FC ghrelin condition compared to Saline mean different of 28% between the 2 studies have shown important role done by ghrelin in non human studies
- Ghrelin important signal which stimulated food intake in humans

Question 12

Leptin resistance

Answer 12

• Although play import role can develop a resistance to hormone resulting in lack of control of appetite and weight gain

Question 13

One reason for Leptin resistance? found in?

Answer 13

• leptin receptors stop functioning properly and cells fail to respond to hormones
• Often found in obese and overweight people making the order to loose weight

Question 14

Leptin resistance means

Answer 14

cannot simply be linked to leptin alone

Question 15

Leptin resistance heymyfield et al study who? and found?

Answer 15

obese adults, doses of leptin 20- 30 times normal level were necessary to produce significant weight reduction
The chemical was not having the effect of it so needed more