motivation II Flashcards
(32 cards)
What are the three primary ways the body uses energy?
- Basal metabolism (55%)
- Digestion of food (33%)
- Active behaviour (12–13%)
What is basal metabolism (BMR)?
Energy used to maintain body heat and other resting functions; varies with body size.
What happens to remaining energy after immediate needs are met?
It is stored as energy reserves.
What is the main fuel for the body?
Glucose.
How many kcal per gram do carbohydrates provide?
~4 kcal/g.
What is the storable form of carbohydrates?
Glycogen, stored in the liver and muscles.
What are amino acids used for, and how many are essential?
Cell building; 9 of 20 are essential.
How many kcal/g do proteins and fats provide?
Proteins: ~4 kcal/g
Fats: ~9 kcal/g
What is the role of vitamins and minerals?
Assist in digestion, cell function, and homeostasis; not a glucose source.
What drives the motivational feeding system?
Avoiding deviation from a homeostatic set-point.
What is the glucostatic theory of appetite?
Eating is regulated by blood glucose levels (glucostat receptors).
What is the lipostatic theory of appetite?
Eating is regulated by body fat levels over the long term.
What effect does damage to the lateral hypothalamus (LH) have?
Decreased feeding (aphagia); LH = “hunger center”.
What effect does damage to the ventromedial hypothalamus (VMH) have?
Increased feeding (hyperphagia); VMH = “satiety center”.
What issue does self-stimulation research raise for the dual-centre hypothesis?
LH stimulation causes various behaviours, not just feeding (e.g., drinking, fighting, mating).
What hormones increase hunger?
Ghrelin and orexin.
What hormones promote satiety (stop eating)?
CCK, Peptide YY (PYY), and Leptin.
What is leptin and where is it produced?
A satiety hormone from adipose tissue that acts on the hypothalamus.
What happens in genetic leptin deficiency?
Leads to obesity due to impaired satiety signaling.
What are the hunger drive signals?
Lateral Hypothalamus
Hormones like Ghrelin and Orexin
What are satiety signals?
Ventromedial Hypothalamus
Hormones like CCK, PYY, and Leptin
What non-homeostatic factors influence eating?
Learned associations
Sensory cues (taste, smell)
Emotional states
What is anticipatory eating in babies?
From 3–6 months, they eat more at night anticipating hunger, not relieving it.
How do rats show anticipatory eating?
They increase food intake before their rest period, guided by internal clocks.
