Appetite Regulation 04.12.23 Flashcards
Define appetite
Desire to eat food
Define anorexia (acutely)
Lack of appetite
Define satiety
Feeling of fullness - disappearance of appetite after a meal
Define body mass index (BMI)
Weight (kg) / height (m squared)
What are the ranges for BMI?
<18.5 underweight
18.5 - 24.9 normal
25.0 - 29.9 overweight
30.0 - 39.9 obese
>40 morbidly obese
Risks of obesity (7)
Type II diabetes
Hypertension
Coronary artery disease
Stroke
Osteoarthritis
Obstructive sleep apnoea
Carcinoma —> breast, endometrium, prostate, colon
ESPECIALLY abdominal (visceral) rather than subcutaneous fat
Which part of the brain plays a key role in appetite regulation?
Hypothalamus
What are the 3 parts of the body which regulate appetite?
Adipose tissue
GI tract
Hypothalamus
What does leptin do? Where is it expressed?
Binds to leptin receptor in hypothalamus and switches off appetite and is immunostimulatory
SO when fat cell mass is increase, there is increased leptin + insulin, then increased action in hypothalamus, activates POMC neuron which decreases food intake
Expressed in white fat
What is peptide YY (PYY)? What does it do?
Binds to NPY receptors, secreted by neuroendocrine cells in ileum, pancreas and colon in response to food, inhibits gastric motility, reduces appetite.
What does cholecystokinin do?
Receptors in pyloric sphincter
- delays gastric emptying
- gall bladder contraction
- insulin release
and via vagus - satiety
What does ghrelin do?
stimulates - Growth hormone release
- appetite - orexigenic
Blood levels high when fasting, fall on re-feeding
Levels lower after gastric bypass surgery
Expressed in stomach
What are the 7 key regulators for AMPK in the hypothalamus?
NPY
Glucose
Insulin
Ghrelin
Leptin
aMSH
AgRP
