KIN 470 1st Edition Lecture 8Running speedVO2 = (.2 * s) + (.9*s* G) +3.5Cardiovascular responds to exerciseMyocardial O2 useAt rest uses 70 to 80 percentDuring exercise, flow must increase 5-7 fold to meet O2 demandVasodilationAdenosineHypoxiaSympathetic nervous system hormonesSubstrate as a function of expenditure-At rest the heart will break down fatty acids to generate energy 80%-cardiac muscle can use lactate as an energy source-task lactate and rapidly converts it to pyruvate-during heavy exercises- lactate is the preferred substratecardiac output-the amount of blood pumped by the heart each minute--product of heart rate and stroke volumeQ= HR * SVHeart rate decreases with endurance rate and the SV increases with endurance trainingThese 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.REST- So the trained male and untrained male has the same cardiac outputMAX EXERCISE- untrained will have a lower cardiac outputEven the heart beats on its own, we have nerves that influence the rate and constraint of the contraction-sympathetic and parasympathetic nervous systempara-slow down, vagus nerves, synapses on SA and AV node and when it releases Acetylcholine it will slow down the firing of nervessym- speed up, SA and AV node and throughout the ventricles,can have two influences on the heartaccelerate heart rate, when releases norepinephrine influence on the strength of contractionbeta-blockage and heart ratedecrease HRregulate SV-EDV-amount of blood that comes back at the end of diastole/ preload-average aortic blood pressure-pressure the heart must pump against to eject blood/ afterload-strength of the ventricular contraction-contractilityincrease diastolic volume that will increase stroke volumefrank-starling—increase end diastolic volume increase stroke volumeforce length relationshipvenoconstriction skeletal muscle pump-one way vavlue- to prevent backflow-when muscle contracts pushes values open-when muscle relaxes gets stuck thereincrease afterload decrease stroke