Eating is partly controlled by the digestive tract, the hypothalamus and cognitive factorsThe digestive system: brings macromolecules into the body via breakdown (hydrochloric acid, pepsin, etc) and absorption of essential nutrients and energy molecules.Three classes: lipids (fats), amino acids (building blocks of proteins), and glycogens (starches and sugars)Lipids provide approximately 85% of stored energy (adipose cells), whereas amino acids (14.5%) and glycogens (liver; 0.5%) provide the rest!Long-term Regulation of Feeding BehaviorEnergy BalancePrandial state: Anabolism: Energy storage as glycogen and triglycerides (fats) during and shortly after food intake.Postabsorptive state: Catabolism: Breaking down complex macromolecules from storage.Lipostatic HypothesisProposed by Gordon Kennedy (1953)Leptin discovered by Jeffrey Friedman’sgroup in 1994Genetic Leptin deficiency = dysregulation of body fat- can be reversed by leptin treatmentStudies indicating role oflateral and ventromedial hypothalamusLateral hypothalamus lesions = anorexia;Ventromedial nucleus lesions = obesityLeptin Regulation of HypothalamusLateral hypothalamus lesions = anorexia;Ventromedial nucleus lesions = obesityLeptin Regulation of Hypothalamus- Peripheral adipose cells release leptin into blood supply, which eventually reaches the brain;Leptin receptors located on neurons in hypothalamic Arcuate nucleus;Response to Elevated LeptinActivated arcuate neurons release αMSH and CART peptides (anorectic peptides – reduce appetite);Activates paraventricular nucleus neurons, which releases ACTH and TSH (humoral), and project to intermediolateral gray matter of spinal cord (sympathetic activation);Inhibits lateral hypothalamus – reduces feeding behaviors (somatic).Response to Decreased LeptinActivated arcuate neurons release NPY and AgRP peptides (orexigenic peptides – increase appetite);Inhibit paraventricular nucleus neurons, which reduces ACTH and TSH (humoral), and activate parasympathetic system;Stimulate lateral hypothalamus – increase feeding behaviors (somatic).NRSC 2100 1st Edition Lecture 23Energy Balance: the control of food intakeEating is partly controlled by the digestive tract, the hypothalamus and cognitive factors- The digestive system: brings macromolecules into the body via breakdown (hydrochloric acid, pepsin, etc) and absorption of essential nutrients and energy molecules.Three classes: lipids (fats), amino acids (building blocks of proteins), and glycogens (starches andsugars)Lipids provide approximately 85% of stored energy (adipose cells), whereas amino acids (14.5%)and glycogens (liver; 0.5%) provide the rest!Long-term Regulation of Feeding BehaviorEnergy Balance• Prandial state: Anabolism: Energy storage as glycogen and triglycerides (fats) during and shortly after food intake.• Postabsorptive state: Catabolism: Breaking down complex macromolecules from storage.Lipostatic Hypothesis- Proposed by Gordon Kennedy (1953)- Leptin discovered by Jeffrey Friedman’s group in 1994Genetic Leptin deficiency = dysregulation of body fat - can be reversed by leptin treatmentStudies indicating role oflateral and ventromedial hypothalamusLateral hypothalamus lesions = anorexia;Ventromedial nucleus lesions = obesityLeptin Regulation of HypothalamusLateral hypothalamus lesions = anorexia;Ventromedial nucleus lesions = obesityLeptin Regulation of Hypothalamus- Peripheral adipose cells release leptin into blood supply, which eventually reaches the brain;These notes represent a detailed interpretation of the professor’s lecture. GradeBuddy is best used as a supplement to your own notes, not as a substitute.-Leptin receptors located on neurons in hypothalamic Arcuate nucleus;Response to Elevated LeptinActivated arcuate neurons release αMSH and CART peptides (anorectic peptides – reduce appetite);- Activates paraventricular nucleus neurons, which releases ACTH and TSH (humoral), and project to intermediolateral gray matter of spinal cord (sympathetic activation);- Inhibits lateral hypothalamus – reduces feeding behaviors (somatic).Response to Decreased LeptinActivated arcuate neurons release NPY and AgRP peptides (orexigenic peptides – increase appetite);- Inhibit paraventricular nucleus neurons, which reduces ACTH and TSH (humoral), and activate parasympathetic system;- Stimulate lateral hypothalamus – increase feeding behaviors