CPPS303 XIAO Lecture 9 Neural Regul Metab March_28_2025 (1) Flashcards
What is energy homeostasis?
The body’s ability to achieve an internal constant and a relatively stable environment.
How is energy homeostasis achieved?
By a balance of food intake and energy expenditure.
How is glucose homeostasis achieved?
By glucose production and utilization.
What role does the hypothalamus play in energy homeostasis?
It is primarily responsible for the regulation of energy homeostasis.
What do specialized neuronal networks in the brain do?
They coordinate adaptive changes in food intake and energy expenditure in response to altered metabolic conditions.
What systems are integrated by the brain to maintain energy homeostasis?
Metabolic signals from peripheral tissues such as liver, pancreas, adipose tissue, gut, and muscle.
What hormones and nutrients do NPY/AgRP and POMC neurons sense?
They sense the body’s energy state through hormones and nutrients.
What is the function of the nucleus of the solitary tract (NTS)?
It responds to satiety signals and activates vagal afferents to reduce food intake.
What pathways are involved in thermogenesis regulation?
The POA-DMN-rRPa pathway promotes brown adipose tissue thermogenesis.
What signals does the GI tract generate to inform the CNS?
Neural signals, gut hormones, bile acids, gut microbiota, and lipids.
True or False: Gut lipid sensing can inhibit food intake.
True.
What substances synthesized in the small intestine reduce food intake?
Lipids such as oleoylethanolamide and N-acylphosphatidylethanolamine.
What does the brain use to regulate glucose metabolism?
Peripheral metabolic signals through hormones (e.g., insulin, leptin) and nutrients (e.g., glucose, free fatty acids).
Fill in the blank: The main sites of convergence for metabolic signals are the _______ and brain stem.
[hypothalamus]
What is the role of the autonomic nervous system in glucose homeostasis?
It modulates pancreatic insulin/glucagon secretion, hepatic glucose production, and skeletal muscle glucose uptake.
What do peripheral glucose sensors include?
Innervation of hepatic portal vein and neurons in circumventricular areas.
What happens when triglycerides enter the upper intestine?
They are digested by lipases to form long-chain fatty acids (LCFA).
How does CCK affect food intake?
It binds to CCK-A receptor on vagal afferents, suppressing food intake.
What is the function of the gut-brain-liver axis?
To regulate glucose production and concentration.
What effect do lipids have on the brain-liver axis?
They activate a neuronal negative-feedback system to regulate peripheral glucose homeostasis.
What is enhanced after gastric-bypass surgery?
Nutrient sensing in the gut.
What enhances nutrient sensing in the gut after gastric-bypass surgery?
A portal vein-brain-liver axis triggers lower hepatic glucose production
This mechanism is significant for understanding metabolic changes post-surgery.
What does nutrient sensing in the gut activate to regulate peripheral glucose uptake?
A portal-brain-muscle axis
This axis plays a critical role in glucose metabolism.
What are the consequences of disrupted nutrient-sensing mechanisms in diabetes and obesity?
Dysregulation of glucose levels
This disruption can lead to complications in managing blood sugar levels.
