35-RegulationOfFoodIntake Flashcards Preview

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Flashcards in 35-RegulationOfFoodIntake Deck (25)
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1

short-term mechanisms of satiety sensing (x4)

- oropharyngeal receptors
- gastric distention
- intestinal nutrient sensing
- post-absorptive satiety (liver factors, portal vein)

2

mechanism of gastric distension sensing

food intake
-> incr. mechanorecptor activity
-> incr. vagal
-> incr. NTS
-> decr. food intake

3

NTS

Nucleus tractus solitarii

4

mechanism of CCK gastric control

1. gallbladder contraction -> incr. bile release -> fat metabolism
2. pyloric constriction
3. gastric contractions

5

mechanism of CCK satiety signaling

CCK released from duodenum
-> incr. CCK receptor activity
-> incr. vagal afferencents (mechanoreceptors)
-> incr. NTS
-> decr. food intake

6

CCK

cholecystokinin, a hormone released from duodenum

7

Ghrelin

hormone released by stomach

8

mechanism of ghrelin cotnrol of satiety

fasting
-> release of ghrelin from stomach
-> incr. appetite (i.e. ghrelin is orexigenic)

9

orexigenic

increases appetite

10

increased leptin signals [increase or decrease] in food intake

decrease

11

site of action for leptin (x2)

- brainstem
- hypothalamus

12

LHA

lateral hypothalamic area

13

lesion of LHA produces ___

aphagia (cessation of feeding)

14

Peptides produced *only* in LHA

orexins

15

Mechanism of LHA control of food intake

Activation of LHA
-> incr. anabolic
-> incr. orexin release
-> food intake

16

PVN

paraventricular nucleus

17

Mechanism of PVN control of food intake

PVN
-> parvocellular neurons send axons to brainstem
-> incr. 'catabolic' neurotransmitter
-> decr. food intake

18

ARC

arcuate nucleus

19

MEL/MSH-positive neurons

melanocortin-positive neurons

20

MEL neurons project to ___ and ___ to [incr. / decr.] food intake

PVN and LHA, decrease

21

Mechanism of ARC / MEL neuron control of food intake

leptin detected in ARC
-> activation of MEL neurons
-> decr. food intake

22

NPY-positive neurons project both to ___ and ___ to [incr. / decr.] food intake

PVN and LHA, increase

23

AgRP

endogenous melanocortin receptor antagonist

24

Interaction between leptin and ARC / NPY to act on food intake

leptin inhibits NPY/AgRP neurons
-> decr. food intake

25

Interaction between ghrelin and ARC to act on food intake

grelin
-> incr. NPY activity
-> incr. food intake