Biological Explanations for Eating Behaviour
- Created by: Amy
- Created on: 15-01-13 23:10
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- Biological Explanations for Eating Behaviour
- Stomach
- Cannon and Washburn
- Washburn swallowed inflated balloon
- inflated
& used measure stomach contractions in relation hunger pangs
- • Washburn’s hunger pangs correlated w/ stomach contractions
- Hungry when balloon was flat
- Suggest presence or absence food in stomach is important signal to brain mechanism of feeding
- However, people who have part or all of stomach removed because of cancer were still able to control food intake
- inflated
& used measure stomach contractions in relation hunger pangs
- Washburn swallowed inflated balloon
- Grehlin
- Hormon produced by the stomach - proportional to how empty it is
- Signals hypothalamusto start eating
- If you inject people with grehlin they increase food intake and body weight
- Cummings et al
- BLood grehlin levels changes between meals
- 6 P's ate lunch then had grehlin levels measured every 5 minutes using blood tests
- Assessed hunger every 30 minutes. Carried on until they wanted evening meal
- Grehlin levels fell after lunch after 70 minutes - lowest
- Then slowly rose til they wanted evening meals
- 5/6 p's grehlin levels were closely correlated with degree of hunger reported supporting the idea that grehlin is a key appetite signal in humans
- Hormon produced by the stomach - proportional to how empty it is
- Cannon and Washburn
- Leptin
- signals body to stop eating
- CCK
- produced by small intestine once food has passed through stomach
- if injected into rats it causes weight loss
- animals with genetic mutation that eliminated CCK system become obese
- if injected into rats it causes weight loss
- produced by small intestine once food has passed through stomach
- Hypothalamus
- Lateral hypothalamus - feeding centre - makes you eat
- Lesioning the LH in rats caused loss of feeding behaviour - even in the presence of food
- Ventromedial hypothalmus - safety centre - not hungry
- Lesioning it - rats over ate and became obese
- Lateral hypothalamus - feeding centre - makes you eat
- Stomach
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