Regulation of Energy Intake and Body Weight regulation

Question 1

set point

Answer 1

Based on animal models, there seems to be a certain weight where their bodies wants to be if energy intake = expenditure

might change over time

Question 2

adaptations to environment: potential mechanisms

Answer 2

genetics, increased energy expenditure, reduced intake/appetite, changes in substrate metabolism (increased fat oxidation, reduced nutrient assimilation)

Question 3

How is energy balance regulated

Answer 3

physiologic or homeostatic mechanisms and non-homeostatic mechanisms

Question 4

physiologic/homeostatic mechanisms of energy balance regulation

Answer 4

short term signals–meal related

lont-term signals - adiposity related

Question 5

non-homeostatic mechanisms for energy balance regulation

Answer 5

reward and motivation, cognitive/executive decisions, environmental cues, social context

Question 6

key area to stimulate eating or not

Answer 6

hypothalamus

Question 7

Lateral nucleus in hypothalamus

Answer 7

“Hunger center”; if blocked, rats stop eating

Question 8

Ventromedial nucleus in hypothalamus

Answer 8

“satiety center”; if knocked out, rats can’t stop eating

Question 9

Leptin

Answer 9

discovered in 90s

- signal associated with stimulating catabolic pathways and inhibiting anabolic to get organism back to steady state

Question 10

what happens to insulin as we gain fat

Answer 10

we get insulin resistance, so insulin is higher

Question 11

hypothalamic nuclei involved in short and long-term regulation of body weight

Answer 11

paraventricular, ventromedial, arcuate, lateral hypothalamus

Question 12

peptides expressed only in LH neurons

Answer 12

melanin concentrating hormone (MCH) and orexins (aka hypocretins) –> induce feeding
these neurons also innervate symp and parasymp preganglionic nuclei in medulla/spinal cord

Question 13

effect of VMN lesions

Answer 13

reset regulated weight to higher level