Chapter 12: WHAT STOPS A MEAL? Flashcards
1
Q
Short-term satiety signals?
A
- immediate effects of eating a particular meal
- begin long before food is digested
2
Q
Long-term satiety signals?
A
- do not control beginning and end of a particular meal.
- in the long run, control intake of calories by modulating sensitivity of brain mechanisms to hunger and satiety signals that they receive
3
Q
gastric factors in short-term satiety?
A
- food moves from stomach into duodenum, nutrient detectors activate
- Info about secretion of cholecystokinin (CCK) is transmitted to brain
- Peptide YY3-36 (PYY) secretion causes feelings of satiety
4
Q
What is cholecystokinin (CCK)?
A
- hormone secreted by duodenum in response to the presence of fat
- regulates gastric motility
- causes gallbladder to contract
- provides satiety signal transmitted to the brain through the vagus nerve
5
Q
What is peptide YY3-36 (PYY)?
A
- released by small intestines
- after a meal in amounts proportional to the calories that were just ingested
- satiety signal
6
Q
what can we say about satiety produced by gastric and duodenal factors?
A
- anticipatory
- they predict that the food in the digestive system will eventually restore the system variables that cause hunger
- liver satiety factors can’t occur until this is done
7
Q
liver factors in short term satiety?
A
- liver received nutrients from the intestines
- sends a signal to brain that produces satiety
- signal continues the satiety that was already produced gastrically
8
Q
insulin factors of short-term satiety?
A
- insulin permits organs other than brain to metabolize glucose
- promotes entry of nutrients into fat cells, the converted into triglycerides
9
Q
Long-term satiety signals?
A
- signals from stored body fats
- LT signals may alter sensitivity to hunger or short-term satiety
- studies of ob mouse led to discovery of leptin
10
Q
What is an ob mouse?
A
- strain with obesity and low metabolic rate
- caused by a mutation of the gene OB that prevents production of leptin
10
Q
What is an ob mouse?
A
- strain with obesity and low metabolic rate
- caused by a mutation of the gene OB that prevents production of leptin
11
Q
What is leptin?
A
- acts as an antiobesity hormone
- secreted by adipose tissue
- decreases food intake
- increases metabolic rate
- does that by inhibiting NPY-secreting neurons in the arcuate nucleus
12
Q
What is the hepatic portal vein?
A
vein that transports blood from the digestive system to the liver
