21- Regulation of Food Intake Flashcards
Neuronal centers that control feeding and satiety are located within the hypothalamus and include…
- Lateral Nucleus (LH)
- Ventromedial Nucleus (VM)
- Paraventricular Nucleus (PV)
- Dorsomedial Nucleus (DM)
- Arcuate Nucleus (Arc)
Crosstalk between ________ and ________ regulations is key to maintain energy balance. The hypothalamus receives many types of signals.
Neural
Hormonal
Most of the integration signaling regulating food intake and energy expenditure happens in the _______ _______.
Arcuate Nucleus
There are two pathways involved for food intake regulation in the Arcuate Nucleus. For this pathway, _______ is released by POMC (pro-opiomelanocortin) neurons. ______ binds to ______ present in second-order neurons (located in PVN). This pathway will decrease food intake.
alpha-MSH (alpha-melanocortin)
alpha-MSH (alpha-melanocortin)
MCR-4
The alpha-MSH pathway is an (ANOREXIGENIC/OREXIGENIC) pathway.
Anorexigenic
***Causing “anorexia” meaning loss of appetite!
There are two pathways involved for food intake regulation in the Arcuate Nucleus. For this pathway, hunger signals stimulate the release of _______ which binds to _______ in second-order neurons (located in PVN).
NPY (Neuropeptide Y)
Y1R
Along with NPY, ________ is also released, which is an antagonist of MCR-4. This is the receptor for alpha-MSH on the second-order neuron (decreases food intake).
AGRP (Agouti-related Peptide)
The NPY pathway is an (ANOREXIGENIC/OREXIGENIC) pathway.
Orexigenic
***Stimulates and increases appetite!
This disorder is early-onset of severe obesity, infertility (hypogonadotropic hypogonadism), hyperphagia, and infections.
Leptin or Leptin receptor gene deficiency
This disorder is early-onset of severe obesity, increased linear growth, hyperphagia, and hyperinsulinemia. Most common known genetic cause of obesity. Homozygous worse than heterozygous.
Melanocortin 4 receptor (MC4R) gene mutation
This disorder presents as neonatal hypotonia, slow infant growth, small hands and feet, mental retardation, hypogonadism, hyperphagia leading to severe obesity, and paradoxically elevated ghrelin.
Prader-Willi Syndrome
Prader-Willi Syndrome is caused by a partial deletion of _________ or loss of _________ expressed genes.
Chromosome 15
Paternally
This disorder presents with obesity, red hair, adrenal insufficiency due to ACTH deficiency, hyperproinsulinemia, hyperphagia, pale skin, and cholestatic jaundice.
POMC (Proopiomelanocortin) deficiency
Several peptides that stimulate satiety and decrease feeding activate receptors on ________ afferents. If this activity is blocked, the amount of material in the stomach no longer influences meal size.
Vagal
_______ is crucial in the interpretation and relaying of peripheral signals. Vagal signaling to the _______ is integrated with info received by the hypothalamus to produce the appropriate feeding behavior and metabolic processes.
NTS
NTS
***NTS = Nucleus of the Tractus Solitarius
What are the steps in the circuit that produces responses related to feeding behavior and metabolism.
Vagal —> NTS —> Hypothalamus
The _________ is able to regulate food intake in response to peripheral signals even in the absence of higher centers’ input.
Hindbrain
This area of the hypothalamus is the hunger center. Its neurons project throughout the brain and release the orexigenic peptides melanin-concentrating hormone (MCH) or orexins A and B.
Lateral Hypothalamic Area (LHA)
***Same as Lateral Nucleus (LH)