endocrinology- regulation of appetite Flashcards
define apetite
the desire to eat food
define satiety
feeling of fullness- disappearance of appetite after a meal
how can body mass index be calculated?
weight (Kg)/ Height (m^2)
what is the BMI category for being underweight?
< 18.5
what is the BMI category for being normal weight?
18.5- 24.9
what is the BMI category for being overweight?
25.0-29.9
what is the BMI category for being obese ?
30.0-39.9
what is the BMI category for being morbidly obese ?
> 40
what are the risks of obesity?
-Type II diabetes
-Hypertension
-Coronary artery disease
-Stroke
-Osteoarthritis
-Obstructive sleep apnoea
- carcinomas
which carcinomas increase the risk of obesity?
-Breast
-Endometrium
-Prostate
-Colon
why do we eat ?
we have an internal physiological drive to eat
what does our internal physiological drive to eat prompt?
thoughts of food and motivates food consumption
describe the external physiological drive to eat
this can occur sometimes even in the absence of hunger- for example in a buffet where you have lots of options
what plays a central role in appetite regulation?
hypothalamus
what is the effect of highly refined sugar food?
quick and short satiety
what is the effect of low glycemic index foods?
better
what is the effect of high protein foods?
prolonged satiety
what is the effect of high fat foods?
stimulates and entices people to eat more
how many peptide YY amino acids are there ?
36
what is peptide YY structurally similar to?
NPY
what does peptide YY bind to?
NPY receptors
what secretes peptide YY?
Secreted by:
- neuroendocrine cells in ileum
-pancreas
- colon
in response to food
what does peptide YY inhibit?
gastric motility
what is the effect of peptide YY?
reduces appetite
where are cholecystokinin receptors?
Receptors in pyloric sphincter
what is the effect of cholecystokinin?
-Delays gastric emptying
-Gall bladder contraction
-Insulin release
what other way can cholecystokinin be released?
via vagus - satiety
what stimulates appetite ?
olfactory
gustatory
cognitive
visual stimuli
what stimulates food intake?
Ghrelin
what increases satiety?
stretch receptors in stomach
what increases satiety TO STOP FEEDING?
the release of:
- CCK
-GLP
-insulin
-Peptide YY
what is the lateral hypothalamus the centre of?
hunger
what is the ventromedial hypothalamic nucleus the centre of?
satiety centre
what does leptin bind to?
leptin receptor
where are leptin receptors?
- cytokine receptor family
- in hypothalamus
what does leptin do?
switches off appetite and is immunostimulatory