appetite Flashcards
what are the characteristics of appetite?
desire to eat
what do you want to eat depending on external and psychological factors e.g smell and temperature
what are the characteristics of hunger?
internal drive to eat
chemical factors in body either central (hypothalamus) or peripheral (blood glucose level drop)
when can you eat
which hormones decrease food intake and how?
where are they released from?
CCK, PP, PYY, GLP-1, leptin
reduce desire to eat
released from small intestine
which hormones increase food intake and how?
where are they released from?
excess glucocorticoids and ghrelin
increase desire to eat
released from stomach and duodenum
effect on hormone levels when stomach empty?
increased level of ghrelin so appetite increase
decreased level of CCK, GLP-1 and PYY
effect on hormone levels when stomach full?
decreased level of ghrelin so appetite decreases
increased levels of CCK, GLP-1 and PYY
describe ghrelin?
gut hormone
released from duodenum and stomach to increase appetite
orexigenic - increases appetite but can overeat as only disappears after 20-30 mins
lower in obese people
how is ghrelin activated and what does it do?
hunger stimulates release from stomach
travels to hypothaalamus which stimulates appetite
eating causes levels to fall and prevent release
describe leptin?
where produced?
when do levels drop completely?
what does it stimulate?
how does leptin work in obese people?
produced in white adipose tissue and correlates with fat stores (more sites)
reduces hunger
levels drop completely during starvation
stimulate release of MSH which suppresses hunger
leptin doesn’t suppress hunger as much in obese people so have high leptin levels but have resistance
describe CCK?
released from?
what does it stimulate?
what does it do?
gut hormone
released from small intestine within 15 mins after start of meal
stimulates gall bladder to release bileto digest fats
reduces urge to eat by decreasing meal size and duration of feeding
describe PP?
released from small intestine
suppresses appetite for a long time
describe PPY?
suppresses appetite for hour after eating and rapdily increases during feeding
describe GLP-1?
released from?
what is release proportional to?
released from SI and colon
amount released proportional to amount of energy taken in
can promote weight loss in high amounts
increased amounts if overweight as resistant
describe OXM?
co-releasedwith GLP-1 and amount released proportional to energy intake
what is adiponectin?
role in energy homeostasis so related to appetite
increase with weight loss and decrease with obesity
