THE BASAL METABOLIC RATE D C MIKULECKY PROFESSOR

THE BASAL METABOLIC RATE D. C. MIKULECKY PROFESSOR OF PHYSIOLOGY VIRGINIA COMMONWEALTH UNIVERSITY

THE METABOLIC RATE = ENERGY EXPENDITURE PER UNIT TIME (Calories/hour)

FACTORS INFLUENCING METABOLIC RATE z. EXERCISE z. FOOD INTAKE z. SHIVERING z. ANXIETY

BASAL METABOLIC RATE z. BODY’S “IDLING SPEED” (THE MINIMAL WAKING RATE OF INTERNAL ENERGY EXPENDITURE) z. DIRECT CALORIMETERY(MEASURE RATE OF HEAT PRODUCTION) z. INDIRECT CALORIMETERY (MEASURE OXYGEN CONSUMPTION) z(SEE LAB NOTES FROM DEC. 2)

FACTORS WHICH INFLUENCE BMR z. FOOD INTAKE z. THYROID HOMONE z. EVEN LOWER LEVELS DURING SLEEP (10 -15%)

ENERGY z. THE CAPACITY TO DO WORK z. THE CALORIE IS THE AMMOUNT OF HEAT ENERGY NECESSARY TO RAISE THE TEMPERATURE OF 1 GRAM OF WATER 1 DEGREE CENTIGRADE z. THE NUTRITIONAL CALORIE IS 1000 CALORIES OR THE KILOCALORIE

ENERGY BALANCE WITH RESPECT TO THE BODY INPUT - OUTPUT = STORAGE OR DEPLETION (CONTINUITY EQUATION ( E/ t = 2 E) ) OUTPUT = INTERNAL WORK + EXTERNAL WORK INTERNAL WORK ------> HEAT

STORAGE AND/OR DEPLETION z NEUTRAL ENERGY BALANCE OCCURS WHEN INPUT AND OUTPUT MATCH z POSITIVE ENERGY BALANCE OCCURS WHEN INTAKE EXCEEDS OUTPUT ENERGY IS STORED AS GLYCOGEN OR FAT z NEGATIVE ENERGY BALANCE OCCURS WHEN OUTPUT EXCEEDS INTAKE- ENERGY STORES ARE DEPLETED

FOOD AS FUEL z. CARBOHYDRATE 4 CAL/G z. PROTEIN 4 CAL/G z. FAT 9 CAL/GRAM z. ETHANOL 7 CAL/G

FOOD AS STORED FUEL z 3500 CALORIES = 1 LB OF BODY MASS

EFFICIENCY OF METABOLISM z 50% GOES TO ATP z 50% GOES TO HEAT

FOOD INTAKE z. CONTROLED BY HYPOTHALAMUS z. FEEDING CENTERS z. SATIETY CENTERS

CONTROL OF FUEL METABOLISM z. GLYCOGENESIS z. GLYCOGENOLYSIS z. GLUCONEOGENESIS z. PROTEIN SYNTHESIS z. PROTEIN DEGRADATION z. FAT SYNTHESIS z. FAT BREAKDOWN

ANABOLISM VS CATABOLISM z. BUILD UP VS BREAKDOWN OF LARGE MOLECULES z. ANABOLISM REQUIRES ENERGY (ATP) z. CATABOLISM: ENERGY PRODUCTION

BLOOD GLUCOSE z ONE GRAM YIELDS ABOUT 4 CALORIES z 70 KG PERSON 2, 000 CALORIES/DAY z NEED 500 G GLUCOSE z AS AN ISOTONIC SOLUTION THAT WOULD BE ABOUT 10 L z THE ACTUAL AMOUNT IS ABOUT 20 G OR ENOUGH FOR 1 HOUR

PANCREATIC HORMONES AND BLOOD GLUCOSE z. INSULIN z. GLUCAGON

INSULIN: ACTION ON BLOOD SUGAR z. BETA CELLS IN ISLETS OF LANGERHANS: INSULIN z. FACILITIES GLUCOSE ENTRY INTO CELLS z. STIMULATES GLYCOGENESIS z. INHIBITS GLYCOGENOLYSIS z. INHIBITS GLUCONEOGENESIS

INSULIN: ACTION ON FAT z. INCREASES TRANSPORT INTO ADIPOSE CELLS z. PROMTES TRIGLYCERIDE SYNTHESIS z. INHIBITS LIPOLYSIS

INSULIN: ACTION ON PROTEIN z. PROMOTES UPTAKE OF AA BY MUSCLE AND OTHER TISSUE z. PROMOTES PROTEIN SYNTHESIS z. INHIBITS PROTEIN DEGRADATION

CONTROL OF INSULIN SECRETION z. NEGATIVE FEEDBACK: BLOOD SUGAR z. BLOOD AA z. GI HORMONES z. PARASYMPATHETIC ACTIVITY

TWO TYPES OF DIABETES MELLITUS z. TYPE I: AUTOIMMUNE DESTRUCTION OF BETA CELLS, LACK OF INSULIN SECRETION z. TYPE II: REDUCED SENSITIVITY OF INSULIN RECEPTORS

ACUTE EFFECTS OF DIABETES MELLITUS z z z EXTRACELLULAR GLUCOSE EXCESS GLUCOSE IN URINE EXCESS FLUID LOSS CIRCULATORY FAILURE RENAL FAILURE NERVOUS SYSTEM MALFUNCTION DUE TO DEHYDRATION EXCESSIVE FOOD INTAKE PROGRESSIVE WEIGHT LOSS MOBILIZTION OF FAT KETOSIS ACIDOSIS COMA AND DEATH

GLUCAGON z PANCREATIC ALPHA CELLS z GENERALLY OPPOSES ACTIONS OF INSULIN z DECREASE GLYCOGEN SYNTHESIS z PROMOTE GLYCOGENOLYSIS z STIMULATE GLUCONEOGENESIS z PROMOTES FAT BREAKDOWN z ONLY IN LIVER: PROTEIN CATABOLISM

EPINEPHRINE, CORTISOL, AND GROWTH HORMONE z. ALL INCREASE BLOOD GLUCOSE AND FATTY ACIDS z. CORTISOL INCREASES BLOOD AA AND DECREASES MUSCLE PROTEIN z. GH DECREASES BLOOD AA AND INCREASES MUSCLE PROTEIN

OVERALL REGULATION OF BLOOD GLUCOSE (+) RELEASE FROM LIVER - ( ) BLOOD GLUCOSE INSULIN (+) EPINEPHRINE AND NOREPINEPHRIN (+) GLUCAGON GLUCOCORTICOIDS - ( ) CONSUMPTION BY MUSCLE AND FAT CELLS - ( ) GH