Valencik: Satiety Lecture Flashcards
suppress appetite
anorexigenic
increase appetite
orexigenic
satiation vs satiety
cessation of hunger vs sensation of being full
Gut hormones that stimulate insulin secretion
incretins
Gastric parietal cells that release gastric acid
oxyntic cells
What are two long-term signals for hunger/satiety?
leptin & insulin
Long term signal Secreted in proportion to fat stores. Eat less, less body fat, less of this signal is produced However, body adapts by: Minimizing energy usage Increasing appetite
leptin
Long term signal
Decreases appetite
insulin
Factors involved in short-term signaling of hunger/satiety
GI tract hormones - modulated by size/number of meals
Ghrelin - makes you hungry
CCK, PYY - make you full
5 neural centers that regulate food intake
lateral nuclei ventromedial nuclei (VMN) paraventricular nuclei (PVN) dorsomedial nuclei (DMN) arcuate nuclei (ARC)
The feeding center
When stimulated, hunger increases a lot
When destroyed, there is no urge to eat
lateral nuclei
The satiety center
When stimulated, there is no urge or a refusal to eat
When destroyed, you have a crazy appetite & may continue to eat until you are obese
ventromedial nuclei
Lesions in this nucleus lead to excessive eating
paraventricular nuclei
Lesions in this nuclei depress eating
dorsomedial nuclei
Site where multiple hormones released from the GI & adipose tissue converge to regulate eating & energy consumption
arcuate nuclei
Two types of neurons found in the arcuate nuclei
anorexigenic –> POMC/CART
orexigenic –> AgRP/NYP
What happens when you stimulate POMC/CART neurons?
production of alpha MSH which binds to MCR-3/4 & decreases food intake & increases sympathetic activity/energy expenditure
POMC/CART neurons release (blank) leading to the activation of melanocortin (blank) and (blank) receptors on the PVN.
Simultaneously, (blank) peptide is released and binds an unknown receptor.
They stimulate the PVN regulation pathways that (blank) eating and (blank) energy expenditure
MSH-alpha; MCR3 and MCR4; CART; inhibit; stimulate
Orexigenic neurons release (blank) and (blank) in response to low energy stores.
(blank) is an antagonist of MCR-4 blocking the signaling by α-MSH in the PVN.
AgRP stimulates the release of (blank) resulting in inhibition of POMC.
AgRP; NYP
AgRP;
GABA;
What is the end result of stimulation of AgRP/NYP neurons?
NYP binds to Y1 receptor, alpha-MSH is blocked from binding to MCR-4;
the PVN are not subject to α-MSH binding to MCR-4 and appetite increases, food intake increases, and energy expenditure decreases