Regulation of Food Intake

Question 1

Satiety Center

Answer 1

Ventromedial nucleus

Question 2

Arcuate Nucleus

Answer 2

Main site of release of food-consumption regulating hormones

*Lacks complete BBB

Question 3

Proopiomelanocortin Neurons

Answer 3

Produce a-MSH and CART which act to decrease food intake and increase energy expenditure by binding to MCR-3 & 4

• MCR projects to NTS to stimulate sympathetic nervous system
• CART negative/MCR-4 mutations => obesity

Question 4

Orexigenic Neurons

Answer 4

Release AgRP and to increase food intake and decrease energy expenditure by inhibiting MCR-3 & 4 and stimulating Y-receptors (appetite) respectively

*Release is inhibited by insulin

Question 5

Nicotine

Answer 5

Nicotine enhances the firing of POMC neurons

=>Increased a-MSH leads to decreased food intake and increased energy expenditure

Question 6

Leptin

Answer 6

Hormone released by adipocytes when amount of fat increases

• Represses NPY/AgRP; stimulates POMC neurons
• Insulin leads to increased release/increased release will decrease insulin levels

Question 7

Ghrelin

Answer 7

Released by the stomach and proximal SI; stimulates AgRP/NPY neurons

• Levels increase w/ stress, loss of sleep, diets, cancer anorexia
• Plasma levels normally rise before meals and fall after

ONLY OREXIGENIC HORMONE

Question 8

GLP-1

Answer 8

Glucagon-like peptide 1

Released throughout the day by L-cells in the ileum and colon

-Stimulates satiety

Question 9

OXM

Answer 9

Secreted by distal intestine in direct proportion to calorie ingestion

Quickly lessens hunger and food intake at a single meal

• Repeated injections would decrease body weight
• Acts much like PYY

Question 10

Endocannabinoids

Answer 10

Stimulates orexigenic system and increases intake of fatty, sweet foods

*Decreased by leptin

Question 11

Anorexia Nervosa Gastric hormones

Answer 11

Elevated NPY; Decreased leptin

Question 12

Feeding Center

Answer 12

Lateral nucleus