Temperature Regulation Anatomy Joke of the Day Nutrient Pools Metabolic States Absorptive occurs either during or after eating when nutrient vol are high in bloddstream and anabolic reactions occur Metabolic States Absorptive Postabsorptive GI tract is empty take nutrients out of storage reserves are broken down maintain blood glucose levels catabolic reaction occurs Hormonal Control Insulin controls absorptive phase released when blood glucose levels are high promotes oxidation of glucose and movement of it out of the blood and promotes conversion of glucose to glucagon Glucagon secreted when blood glucose levels are low stimulates release of stored glucose one process is glycogenolysis breakdown of glycogen to glucose promotes lipolysis breakdown of lipids increases blood glucose levels Neural Control Sympathetic stimulation low blood glucose levels prompts ANS to generate sympathetic impulse which functions in postabsorptive state and will act on lipids adipose and causes them to break down also affects adrenal gland and promotes secretion of epinephrine Epinephrine promotes glycogenolysis and lipolysis acts upon liver skeletal muscle and adipose tissue to break down storage molecules happens because of sympathetic impulse from adrenal glands Liver Functions Produce very low density lipoproteins VLDL density is determined by density of lipid more lipid lower density protein part heavier than lipids produced by liver this is basically cholesterol it is not for energy lipid cannot be broken down into energy liver makes about 85 of cholesterol in body can circulate through body LDLs are the bad cholesterols Break down HDL LDLs are converted to HDLs in the cells which are corculated back to liver as HDLs low in lipid so high density Metabolic Rate Basal metabolic rate BMR amount of energy needed for essential activities of life Colorimeter measures heat of body because body gives off heat when outputting energy measures temp of water when person is submerged into water after fasting for 12 hrs postabsorptive Respirometer measure amount of O2 being used or amount of CO2 being generated taken after fasting for 12 hours and is also postabsorptive Total metabolic rate TMR energy necessary for all the activities of the body Body Temperature Heat Exchange Radiation no direct contact heat just moves through environment Heat Exchange Radiation Conduction transfer through contact heat moves from hot to cold through contact Heat Exchange Radiation Conduction Convection warm airs rises and cold air settles so there is this movement of air increases heat transfer by moving air Heat Exchange Radiation Conduction Convection Evaporation conversion of a liquid to a gas and when this happens there is loss of energy 2 types of water loss in humans insensible water lost in breathing and sensible water loss occurs through sweating and we can control this some Heat Promoting Mechanisms Vasoconstriction blood is kept in deep parts of body and don t go near skin so body can t lose heat Heat Promoting Mechanisms Vasoconstriction Increase metabolic rate non shivering thermogenesis hypothalamus triggers norepinephrine Heat Promoting Mechanisms Vasoconstriction Increase metabolic rate Shivering stimulation of skeletal muscle when any msucle contracts there is heat produced as hair stands up pilli then this keeps in heat Heat Promoting Mechanisms Vasoconstriction Increase metabolic rate Shivering Thyroxine release only imp in infants lose when we get older if the body is cold the hypothalamus causes release of TSHRH look at picture Heat Promoting Mechanisms Vasoconstriction Increase metabolic rate Shivering Thyroxine release Behavioral mechanisms as humans we bundle up in extra clothing and blankets increase physical activity assume certain posture like a ball drink hot drinks Heat Loss Mechanisms Vasodilation increase movement of blood to shell so increase heat transfer Heat Loss Mechanisms Vasodilation Sweating evaporation causes cooling Anatomy Joke of the Day Heat Loss Mechanisms Vasodilation Sweating Behavioral mechanisms loose clothing with light colors sweat sticks to clothes which cools and then cools body decrease activity move to cooler environment Fever Cells release pyrogens Pyrogens cause hypothalamus to release prostaglandins Prostaglandins reset thermostat Vasoconstriction and shivering result Body temperature increases ATP Synthesis Substrate level phosphorylation direct transfer of phosphate to ADP to move it to higher state ATP ATP Synthesis Substrate level phosphorylation Oxidative phosphorylation chemiosmotic process create proton gradient which bump ADP up to high ATP level eventually will involve kreb cycle Carbohydrate Metabolism Glucose enters cells by facilitated diffusion Glucose immediately phosphorylated to glucose 6 phosphate extra glucose comes from ATP non reversible reaction Glycolysis continues and results in formation of 2 molecule of pyruvic acid 2 molecules of NADH and a net gain of 2 molecules of ATP used 2 and made 4 If oxygen is present oxidative phosphorlyation occurs Oxidative Phosphorylation Pyruvic acid converted to acetyl CoA in mitochondria Generates CO2 and NADH Acetyl CoA enters Krebs cycle Generates 2 CO2 2 NADH 1 ATP and 1 FADH2 coenzymes are the important things Reduced Kreb s cycle coenzymes NADH and FADH2 enter electron transport chain Hydrogens used to phosphorylate ADP Generates H2O and 34 ATP Excess Glucose High ATP levels stop glycolysis substrate level Glucose converted to gylcogen Glycogen stored until energy needed Excess Glucose High ATP levels stop Glucose converted to glycolysis gylcogen Glycogen stored until energy needed Drop in blood glucose stimulates glycogenolysis Gluconeogenesis Insufficient glucose don t have enough substrate to enter ATP production availability prompts conversion of glycerol and amino acids Occurs in liver Lipid Metabloism Absorbed lipids broken down by plasma enzymes into glycerol and fatty acids Glycerol converted to glyceraldehyde phosphate lipids can produce a lot of this Glyceraldehyde phosphate converted to pyruvic acid in glycolysis Then enter Kreb s Fatty acids broken into acetic acid in mitochondria Acetic acid fused with CoA to form acetyl CoA Also enters Kreb s Excess Lipids High ATP and glucose levels trigger conversion of glycerol and fatty acids into triglycerides for storage Lipolysis reverses process Protein Metabolism Amino acids deaminated strip off ammonia Deaminated molecules converted to pyruvic