Regulation of Food Intake

Question 1

Integration signals affecting food intake takes place in what area of the hypothalamus

Answer 1

arcuate nucleus

Question 2

POMC (pro-opiomelanocortin) neurons exhibit what effect on feeding

Answer 2

release alpha-melanocyte-stimulating hormone (a-MSH) that binds melanocortin receptors (MC4) on second-order neurons
exhibit an inhibitory effect on food intake and a stimulatory effect on metabolism

Question 3

POMC inhibits

Answer 3

feeding

Question 4

POMC stimulates

Answer 4

metabolism

Question 5

Hunger signals stimulate release of what neuropeptide to increase food intake

Answer 5

NPY (neuropeptide Y)

binds Y1 receptors to increase feeding behavior and storage of calories

Question 6

when NPY is released, what other peptide is released to inhibit the POMC system (remember POMC inhibits feeding behavior)

Answer 6

AgRP - agouti-related peptide an antagonist of the MC4 receptor that inhibits feeding behavior

Question 7

region of the brain that regulates metabolic rate, food intake, body weight

Answer 7

hypothalamus

Question 8

the hypothalamus receives inputs from these 5 stimuli

Answer 8

neural signals from GI tract about stomach filling 
chemical signals from nutrients in food 
signals from GI hormones 
Signals from adipose tissue hormones 
Signals from cerebral cortex

Question 9

leptin stimulates and inhibits which cell population in the arcuate nucleus

Answer 9

the POMC or pro-opiomelanocortin neurons

inhibits NPY-AGRP orexigenic neurons

Question 10

POMC neurons secrete what substance that inhibits feeding

Answer 10

alpha-melanocyte stimulating hormone (a-MSH)

agonist for M4 receptor promoting anorectic singals

Question 11

ghrelin stimulates which cell population in the arcuate nucleus

Answer 11

NPY-AGRP neurons to stimulate food intake

Question 12

orexigenic effects are mediated thorugh what receptors

Answer 12

Y1 receptors of NPY

Question 13

inhibition of MCR3 and MCR4 has what effect on feeding

Answer 13

greatly increases food intake and decfreases energy expenditure (recall MCR4 is a part of the anorexigenic pathway)

Question 14

afferent vagus nerve fibers receive what signals to modulate feeding behavior

Answer 14

CCK, GLP-1, 5-HT 
Leptin 
Lipids 
Glucose
PYY

Question 15

efferent vagus nerve fibers modulate what functions

Answer 15

GI motor and secretory functions
decreased hepatic glucose production
increased glycogen synthesis
increased pancreatic endocrine insulin and exocrine secretion

Question 16

effect of ghrelin

Answer 16

appetite stimulator
secretion peaks brefore mealtime and falls once food has been consumed
stimulates NPY secreting neurons
increased growth hormone secretion

Question 17

ghrelin is produced where in the GI tract

Answer 17

stomach

Question 18

leptin is produced by what cells

Answer 18

adipose tissue

Question 19

leptin exerts what effects on appetite

Answer 19

suppresses ghrelin release
decreased production in hypothalamus of appetite stimulators such as NPY and AGRP
activation of POMC neurons –> a-MSH release
incresaed production of corticotropin-releaseing hormone that decreases food intake
increased sympathetic nerve activity to increase metabolic expenditure
decreased insulin secretion by pancreatic beta cells to decrease energy storage

Question 20

insulin is produced by what cells

Answer 20

beta cells of endocrine pancreas

Question 21

effects of insulin

Answer 21

regulates glucose uptake, storage of absorbed nutrients

Question 22

type 1 DM is an absence of what hormone

Answer 22

sufficient levels of insulin resulting in increased food intake

Question 23

effects of CCK

Answer 23

gallbladder contraction
slows gastric emptying
slows gut motility
increased gastric acid secretion

Question 24

PPY is secreted from what part of the alimentary tract

Answer 24

small intestine, ileum and colon

Question 25

ppy exerts what effect on appetite

Answer 25

decreases appetite

Question 26

oxyntomodulin exerts what effect on the GI tract

Answer 26

reduces gastric motility and secretion | produced form the proguclagon gene and released from SI inresponse to a meal

Question 27

GLP-1 has what effect

Answer 27

potent inducer of glucose-dependent insulin release. GLP1 can influencde food intake by acting on the nucleus of the solitary tract in the brainstem and paraventricular nucleus of hypothalamus

Question 28

roux-en-y gastric bypass RNY invovles what surgical resection

Answer 28

reduce size of stomach to an egg, directly attach the pouch to SI