AAE 350 Exam Questions

Describe the changes in the use of carbohydrate, fat and protein during starvation - Negative nitrogen balance: 12-15g excreted through urine -skeletal muscle broken down to produce glucose using 75g per day of protein -about 160gm of body fat also used -after about a month: 2-4 g nitrogen lost per day, breakdown of skeletal muscle slows (only cells that have to use glucose) Gradual shift in metabolic fuels - 1st: glucose produced from protein breakdown to provide energy -2nd: fat breakdown and metabolism provedes ketones for all tissues except CNS, Red and white blood cells -serum fatty acid levels increase -serum albumin is normal until late in starvation Weight loss: first week a lot of salt and water loss BMR and total energy expenditure decreased in prolonged starvation: decreased activity, increased sleep, decreased body temperature Explain how at least 3 bodily functions adapt to PEM. - -Cardio: muscles reduce in size. CO, HR, and BP decrease. reduce oxygen consumption -Respiratory: muscles catabolized. decrease strength of respiratory muscles, max voluntary ventilation, vital capacity, and max inspiratory pressure. BMR lowered -Immune system: depletion of lymphocytes, defects in antibody production. Decreased immunity -GI: Impaired intestinal absorption of fat and sugars, and decreased rate of glucose absorption. Can lead to intestinal edema which decreases luminal absorption that leads to diarrea Nervous system: Early life PEM leads to decreased brain growth, nerve myelination, neurotransmitter production, velovity of nervous conduction (these are long term effects) Electrolyte changes: Total potassium reduces due to decreased muscle proteins and loss of intracellular potassium How does the body adapt metabolically to malnutrition? - How does the body adapt physiologically to PEM? - - hunger subsides after 2-3 days -defecation stops after 3-4 days -urine output decreased after 1 week (many to 100-700 ml/day) -blood glucose levels drop to 35-65 mg/dl without clinical signs of low blood sugar