KIN 3306 1nd Edition Lecture 9 Outline of Last Lecture I Overview II Basic Definitions III Heart Rate IV Definitions V Hemodynamics VI Blood Distribution Diagram VII Exercise and Blood Flow VIII Autoregulation of Muscle Blood Flow during Exercise IX Oxygen Consumption X Blood Pressure and Exercise Intensity XI Exercise Intensity and the Heart XII SV Increases with Exercise XIII Exercise Intensity and AVO2 Difference XIV Steady State Responses XV Long Duration Exercise XVI Summary of Exercise Response XVII CV Training Adaptations XVIII Key Concepts These 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 Outline of Current Lecture I Red Blood Cell II Hemoglobin III Blood IV Hematocrit V Oxygen Transport VI Myoglobin vs Hemoglobin VII Exercise and Hemoglobin Dissociation VIII Body Temperature pH Continued IX 2 3 Diphosphoglycerate DPG X CO2 Transport in the Blood XI Bicarbonate System XII Central Control of Ventilation XIII Ventilation During Exercise XIV Ventilation and Energy Metabolism XV Ventilatory Threshold XVI Respiratory Limitation to Performance XVII Specific Training Adaptations Current Lecture I Red Blood Cell a Oxygen transport within the blood b Contains Hemoglobin i 98 of oxygen is transported by hemoglobin c No nucleus No mitochondria d Oxygen binds to Hemoglobin II Hemoglobin a Four subunits four O2 b Oxyhemoglobin oxygen is bound c Deoxyhemoglobin oxygen is not bound d Binding increases affinity e Note Each subunit can bind to one O2 molecule Once it binds to one O2 molecule then that will increase the amount that it wants to grab the second Affinity increases as O2 is bound to it Once it has four it will hold tightly to it Once it unloads one it will more readily unload the rest III Blood a Components of Blood i Plasma 1 Liquid portion 2 Ions Hormones Proteins and Nutrients ii Cells Formed Elements 1 Red blood cells carry oxygen 2 White blood cells immunity 3 Platelets clotting IV Hematocrit a Hematocrit percentage of red blood cells in blood b Men 45 c Women 40 d More RBC s more O2 e Note Having a higher hematocrit is beneficial Blood doping is increasing hematocrit which helps carry O2 more efficiently but it is dangerous because it makes the blood thick V Oxygen Transport a b Note This is the O2 Hemoglobin Dissociation Curve The x axis is how much O2 is bound to the hemoglobin We see that when it is fully saturated at 100 is when it is from the lungs The y axis is the amount of O2 at the tissues Hemoglobin is unloading O2 at those tissues that need oxygen It is not a straight line there is a curve relationship During exercise veins at rest is going to be a lot lower c Note The main things are that hemoglobin will hold onto O2 until it gets to the tissues that are lower in O2 It is a curve because once it starts unloading it is quicker to let go of the rest once it gets to those tissues VI Myoglobin vs Hemoglobin a b Note Myoglobin is like hemoglobin but it is in the muscle It holds on to O2 It is a storage place for O2 in the muscle The difference is that myoglobin holds onto O2 longer so it has a higher affinity until it gets to a super low PO2 Then it will start releasing it It is a curve also so once it releases one it will release the rest quicker Myoglobin will stay bound until during exercise when your PO2 is so low OR at the beginning of exercise myoglobin might release its O2 and can be used Myoglobin has a greater affinity for O2 VII Exercise and Hemoglobin Dissociation a Effect of Body Temperature i Increase ATP demand increase metabolic rate increase body temperature ii Decrease bond strength between Hb and O2 iii Increase O2 extraction at tissue level b Effect of pH Bohr Effect i Heavy exercise increase H decrease in pH acidic ii Decrease bond strength between Hb and O2 iii Increase O2 extraction at tissue level c Note a couple things affect the curve during acute exercise Body temperature and acidity is what we re focusing on Body temperature increases during exercise and this will decrease the bond strength between hemoglobin and oxygen It will make hemoglobin let go of its O2 easier than at normal resting BP This is beneficial As for pH we have acid as a byproduct of exercise so blood pH drops then that will affect the bond strength and decrease it so we can extract O2 more efficiently VIII Body Temperature pH Continued a b Note temperature is on the left and pH is on the right The middle line is the resting numbers As BP increases the curve shifts to the right As acidity drops curve shifts to the right which means that we are extracting O2 easier at high PO2s Shifts to the right is the important thing A decrease in pH and an increase in acidity and an increase in temperature work together and allow us to meet the metabolic demands during exercise IX 2 3 Diphosphoglycerate DPG a Red blood cells do not contain nuclei or mitochondria thus they make ATP using anaerobic glycolysis b 2 3 DPG is a byproduct of this reaction c Exercise sea level little effect d Exercise high altitude increase in O2 extraction at the tissue level e Note another thing that will affect this curve is DPG It is one of the intermediates during glycolysis Red blood cells don t have mitochondria so all the energy production is anaerobic through anaerobic glycolysis DPG is an intermediate of glycolysis and during training at altitude we see a high level of DPG in blood and this has similar effects as the previous slide It decreases the bond with hemoglobin and allows us to extract more O2 X CO2 Transport in the Blood a Bound to Hb 20 carbaminohemoglobin i Binds to a different site than oxygen ii Affected by oxygenation and PCO2 b Dissolved in plasma 10 c Bicarbonate system 70 i Last time role in buffering H ii CO2 H2O H2CO3 H HCO3d Note CO2 is a big by product of exercise CO2 travels through the blood and it can also bind to hemoglobin but it binds to a different place on hemoglobin and it affect the affinity of O2 CO2 can also travel as free CO2 in the blood Most of it will travel as bicarbonate through the blood In the bicarbonate system it takes the acid and combines it with bicarbonate and that converts to carbonic acid and then that turns into CO2 and that is exhaled XI Bicarbonate System a Occurs within RBS b HCO3 into bloodstream Cl into RBC XII Central Control of Ventilation a Respiratory Centers in the brain i Located within brain stem ii Establish rate and depth b Cortex i