15. Regulation of Food Intake Flashcards
What two types of neurons make up the orexigenic signals?
Neuropeptide Y neurons.
Agouti-related peptide (AgRP) neurons.
What indirect function of leptin will result in decreased appetite?
(Indirect meaning not the direct activity on the POMC/CART or AgRP/NPY neurons.)
Inhibition of ghrelin release.
Describe the basic technique of a biliopancreatic division with duodenal switch surgery.
A sleeve gastrectomy performed in the majority of the small intestine is bypassed – meaning the late jejunum or ileum is attached directly to the stomach. The rest of the intestine remains as a “biliopancreatic loop” in order to transport digestive enzymes from the pancreas, gallbladder, and liver into the non-bypassed portion of small intestine “the common loop.”
What genetic factor and physiological factor play a role in developing and maintaining anorexia nervosa?
AgRP may have a polymorphism and therefore not be as potent of a reward mechanism.
Due to chronic fasting the patient establishes ghrelin resistance.
What three outside signaling molecules stimulate the anorexigenic pathway?
Leptin.
Insulin.
CCK.
(The “I just ate” signals.)
What region of the brain coordinates neural inputs regarding satiety from the vagal efferent and afferents?
The nucleus tractus solitarius.
What hormone is released by POMC / CART neurons?
Alpha-MSH
What is the basic function of amylin?
Inhibits NPY release and has anorexic effects.
What is the basic affect of pancreatic peptide on appetite?
Decreases food intake via Y4R
What is the basic function of peptide YY?
Released by the ileum and colon following a meal to activate POMC by inhibition of an inhibitor. Inhibits NPY/AgRP.
Anorexogenic effect.
What are the functions of ghrelin?
Increases appetite.
Increases gastric motility.
Increases gastric acid secretion.
Increases adipogenesis.
Decreases insulin secretion.
What is released by NPY/AgRP neurons?
NPY
How does the AgRP/NPY cell type inhibit the POMC/CART cell type?
AgRP blocks the action of alpha MSH, by acting as an antagonist for MCR 4
What is stimulated by leptin, eventually resulting in decreased food intake?
Leptin receptors on both POMC / CART and AgRP / NPY.
What is the general function of glucagon-like peptide-1?
Reduces food intake.
Suppresses glucagon secretion.
Delays gastric emptying.
Why might someone perform biliopancreatic division with duodenal switch over a gastric bypass?
Weight loss in biliopancreatic division with duodenal switch is better than that with gastric bypass.
What is the basic function of oxyntomodulin?
Decreases gastric motility and secretions.
Has an anorexic effect.
What is the basic function of insulin?
Decreases appetite and increases metabolism.
Describe the basic technique of a Roux-en-Y gastric bypass.
A gastric pouch is formed from the stomach and the duodenum is bypassed. Therefore the jejunum is connected directly to the stomach pouch.
What two types of neurons make up the anorexigenic signals?
The pro-opiomelanocortin (POMC) neurons.
The cocaine and amphetamine related transcript (CART) neurons.
To what can alpha-MSH bind?
MCR-4 on second-order neurons.
MCR-3 on the AgRP/NPY neurons.
What is the basic function of glucagon?
Reduces food intake. (And a million other things)
What indirect action of ghrelin will increase appetite?
(Indirect meaning not the direct activity on the POMC/CART or AgRP/NPY neurons.)
Decreased secretion of leptin.
What are the known signs and complications of bulimia nervosa?
Swollen parotid glands.
Acid reflux and dysfunctional lower esophageal sphincter.
Esophagitis / Barrett’s esophagus.
Heart and electrolyte disturbances.
Mallory Weiss tear:
What is ghrelin’s receptor?
What is ghrelin activating with this receptor?
Growth hormone secretagogue receptors.
(GHSR)
NPY releasing neurons.
(AgRP and POMC/CART are not affected by ghrelin except indirectly by interfering with leptin)
