15- Hunger and Satiety Flashcards
Hypovolemic thirst stimulated by
Reduced extracellular volume
Osmotic thirst (cellular dehydration) stimulated by
High extracellular solute concentration
BMI =
Mass/(height)2
The body uses energy in 3 primary ways
- Basal Metabolism: 55%
- Digestion of food: 33%
- Active Behavioural processes: 12-13%
Primary ‘fuel’ for the body
Glucose
What is an error detector
Compares actual versus set-point state
What is an error correction mechanism
Negative feedback mechanism
Two basic types of set-points are
- Glucostatic Set-Point Theory: Eating is controlled by deviations from a hypothetical blood glucose
- Lipostatic Theory: Eating is controlled by a hypothetical body-fat set-point
Damage to lateral hypothalamus (LH) causes
A large decrease in feeding (aphagia) & reduced body size
Damage to the ventromedial hypothalamus (VMH) causes
Increasing feeding (hyperphagia)
Recent work shows that the LH contains
Glucose receptors (along with the liver)
LH brain self-stimulation is what in rats
Rewarding
Brain sites where stimulation causes eating are the same sites where
Self-stimulation is rewarding
What are ghrelin and orexins
Peptide hormones secreted in the gut and from adipose tissue + hypothalamus, respectively
What does Orexin and Ghrelin administration do
Increase hunger
