W.6: Alteration in energy balance Flashcards
What is the compound in which a lean healthy person stores the most energy?
Fat
The tissue that exclusively burns glucose?
Retina and RBCs
In normal conditions, ratio of brain glucose utilization compared to the entire body in percent?
60-70%
BMR is influenced by (6 factors)
Age, body surface, temperature, sex, degree of nutrient supply, emotional state
Indirect calorimetry
Measurement of exhaled CO2 and inhaled O2 in an isolated system
Conditions with increased energy need
Pregnancy, fever, infection, wound healing, trauma, tumor, medications
Insulin activates what processes
Glycogen synthesis, protein synthesis, fat synthesis
Insulin inhibits what processes
Lipolysis, gluconeogenesis
Glucagon and epinephrine stimulates what processes
Lipolysis, gluconeogenesis, glycogenolysis
Cortisol stimulates what processes
Gluconeogenesis, proteolysis
ACTH, CTH, thyroid hormone enhances what process
Lipolysis
Elevated glucose levels after a meal enhances ……. by..?
Enhances fatty acid synthesis, by increasing cytoplasmic citrate and NADPH-concentrations, and by providing an alpha-glycerophosphate source
Elevated FFA levels during starvation leads to..
Inhibition of cellular glucose uptake and it enhances glycogenolysis and gluconeogenesis
Where do we store protein? How many percent of our body mass?
Muscle, 12-17% of body weight
Where do we store carbohydrates? How many percent of our body mass?
Liver and muscle as glycogen, blood as sugar. Less than 1 percent of body mass
Where do we store fat? How many percent of our body mass?
Stored in adipose tissue, 15-25% of body mass
What is the energy source of connective tissue in starvation?
Fatty acids
Besides glucose, what is burnt by the brain in adapted (late) starvation?
Ketone bodies
Appropriate laboratory test if chronic malnutrition is suspected?
Se Albumin
Processes taking place in the postprandial period (0-6 hours after meal)
Protein synthesis, glycogen synthesis, triglyceride synthesis (high insulin/glucagon ratio)
Processes taking place in the postabsorption period (6-24 hours after meal)
Glycogenolysis (while stores last), gluconegenesis (liver)
- Glucose consumption in muscle and fat tissue decreases -> uses fat instead
- Ketone body production in the liver
Processes taking place in the early, non adapted starvation (1-3 days after meal)
- Glucose source: Gluconeigenesis (liver and renal cortex)
- Glucose consumption: Minimal in muscle, decreases in brain (use of ketone bodies increases)
- Now high level of ketone body production
Processes taking place in the late, adapted starvation (>3 days after meal)
- Glucose sourse: Gluconeogenesis
- Glucose consumption: Decreases in the brain (2:1 ratio of ketone bodies to glucose)
(Always unchanged glucose consumption in RBC and renal medulla)
Clinical conditions causing ketosis
Starvation/fasting, untreated diabetes mellitus 1, alcoholism, ketogenic diet, vomiting (mostly in children)
What conditions can be treated with a ketogenic diet?
Certain epileptic conditions, and its also a way of loosing weight
2 diseases caused by insufficient protein intake in childhood
Kwashiorkor, Marasmus
Three criteria for suspicion of malnutrition
- 10% unwanted weight loss in 3 months
- Body mass <90% of ideal
- BMI <18,5 kg/m2
Definition of cachexia
Significant weight loss caused by certain conditions, where the decrease of body mass cannot be explained by the decreased calorie intake alone. It affects mostly the muscle mass
During cachexia, the ubiquitin-proteasome system is activated. What are its components?
Inflammatory mediators: TNFalpha, IL-6, IL-1beta
Mediators produced by the tumor: Proteolysis inducing factor (PIF)
Most important peptide synthesized in adipose tissue that affects food intake?
Leptin
A complication of the respiratory system in obesity?
Pickwick syndrome
Hormone stimulating lipogenesis?
Insulin
If we have an increase in adipose tissue, leptin levels will… and lead to…?
Leptin levels will rise -> decreased food intake, increased energy expenditure, sympathetic activity increased
