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IB Sports, Exercise and Health Science Topic 2: Exercise Physiology: Cardiovascular System 2.2.1: Composition of Blood 2.2.2: Composition of Blood - Match the statements: Red blood cells are called….. The main function of red blood cells In the red blood cells haemoglobin helps…. White blood cells protects the body… White blood cells are also called…. White blood cells are produced… The platelets job is to… Platelets are smaller parts… Plasma is 90%water and makes up… Plasma contains plasma proteins that help… …erythrocytes …is to transport oxygen …the transportation of oxygen to the working muscles. … by going to the source of infection. Leukocytes. …in both the long bones and the lymph tissues of the body. …to clot the blood. …of larger cells. ...55% of the volume of blood …the circulation between cells and tissues IB Sports, Exercise and Health Science Topic 2: Exercise Physiology: Cardiovascular System Section 2 Blood Flow Song: Go to the following link and write out the lyrics for the song. http://www.youtube.com/watch?v=gIXcWE0bTwY IB Sports, Exercise and Health Science Topic 2: Exercise Physiology: Cardiovascular System 2.2.3 Describe the Anatomy of the heart Using the terms at the bottom of the page, label the diagram. Once you have finished, match each one to its correct definition. Aorta Pulmonary Artery Pulmonary Veins Semilunar Valves Bicuspid valve Tricuspid valve Left Atrium Right Atrium Left Ventricle Vena Cava Aorta Pulmonary veins Right Ventricle Transports oxygenated blood from the heart to the body Transport oxygenated blood from the lungs to the heart Vena cava Transport deoxygenated blood from the body to the heart Pulmonary artery Bicuspid valve Tricuspid valve Transports deoxygenated blood from the heart to the lungs Prevent blood flowing back from the ventricles into the atria Right atrium Right ventricle Pump deoxygenated blood to the lungs Left atrium Left ventricle Pump oxygenated blood from the lungs to the body Semilunar valves Prevent blood from flowing back into the heart IB Sports, Exercise and Health Science Topic 2: Exercise Physiology: Cardiovascular System 2.2.5 Outline the relationship between pulmonary and systemic circulation Pulmonary and systemic circulation are two separate cardiovascular systems for distributing oxygen-rich blood from the heart and lungs throughout the body. The blood that is returned to the heart from the body via the veins has been depleted of oxygen, or deoxygenated, and must receive oxygen again in the lungs before being re-circulated back to the body. Pulmonary circulation is the process by which the deoxygenated blood is pumped from the heart to the lungs, receives oxygen there, and is pumped back into the heart. Systemic circulation is the process by which this oxygenated blood is pumped from the heart and distributed via the arteries throughout the body, delivering oxygen and other vital nutrients to the organs, muscles, and other tissues that require it. It is then returned to the heart by the veins, where the process of pulmonary and systemic circulation begins again. http://www.wisegeekhealth.com/what-is-the-relationship-between-pulmonary-andsystemic-circulation.htm Describe in detail (13 steps) a pumping cycle starting with blood, low on oxygen coming from the upper part of the body and finishing with the oxygen rich blood going into the aorta. Step 1 2 3 4 5 6 7 8 9 10 11 12 IB Sports, Exercise and Health Science Topic 2: Exercise Physiology: Cardiovascular System 13 1. Blood- low on oxygen- flows towards the right atrium via the Vena Cava inferior and superior. 2. The tricuspid valve opens and blood is pumped into right ventricle of your heart. 3. Right Ventricle contracts and blood passes the pulmonary valve and enters the pulmonary artery. 4. Blood goes to your lung and becomes oxygen rich. 5. The L atrium contracts and blood goes to the L ventricle through the mitral valve. 6. The L ventricle contracts and the aortic valve opens. 7. The aortic valve quickly closes (prevent blood from going back). 8. The right atrium fills with blood and when full contracts. 9. When the R ventricle is full of blood the tricuspid valve closes (prevent blood flowing back into R atrium). 10. The pulmonary valve closes to prevent blood from going back into R ventricle. 11. This oxygen rich blood returns from lungs through pulmonary veins and fills your L atrium. 12. The mitral valve closes when the L ventricle is full of blood. 13. Oxygen rich blood is pumped into the aorta. 1 2 3 4 5 6 7 8 Blood- low on oxygen- flows towards the right atrium via the Vena Cava inferior and superior The right atrium fills with blood and when full contracts The tricuspid valve opens and blood is pumped into right ventricle of your heart When the R ventricle is full of blood the tricuspid valve closes (prevent blood flowing back into R atrium) Right Ventricle contracts and blood passes the pulmonary valve and enters the pulmonary artery The pulmonary valve closes to prevent blood from going back into R ventricle Blood goes to your lung and becomes oxygen rich 10 This oxygen rich blood returns from lungs through pulmonary veins and fills your L atrium The L atrium contracts and blood goes to the L ventricle through the mitral valve. The mitral valve closes when the L ventricle is full of blood 11 The L ventricle contracts and the aortic valve opens 12 Oxygen rich blood is pumped into the aorta 13 The aortic valve quickly closes (prevent blood from going back) 9 IB Sports, Exercise and Health Science Topic 2: Exercise Physiology: Cardiovascular System 2.2.4 Describe the intrinsic and extrinsic regulation of heart rate and the sequence of excitation of the heart muscle. Define Key Word Definition Myocyte A myocyte (also known as a muscle cell or muscle fiber) is the type of cell found in muscle tissue. Myocytes are long, tubular cells that develop from myoblasts to form muscles in a process known as myogenesis. There are various specialized forms of myocytes: cardiac, skeletal, and smooth muscle cells, with various properties. Cardiac myocytes are responsible for generating the electrical impulses that control the heart rate, among other things. Sino-atrial node The SA node is the heart's natural pacemaker. Stimulates atria to contract. AV node stimulates ventricles to contract. Acts as a bridge pathway (electrical relay station) between the upper chambers and lower chambers. An action potential is a short-lasting event in which the electrical membrane potential of a cell rapidly rises and falls, following a consistent trajectory. Atrio-ventricular mode Action Potential Purinje fibres (Bundle of His) Myocardial contraction Autonomic nervous system Purkinje fibers are specialized muscle fibers found in the heart. Their function is to relay impulses from the bundle to the ventricles, causing a contraction. Refers to the contraction of the heart muscle. Division of the peripheral nervous system; controls involuntary activities not under conscious control, such as heart rate and digestion. The above definitions taken from wikipedia and wisegeek. IB Sports, Exercise and Health Science Topic 2: Exercise Physiology: Cardiovascular System Annotate and Explain the stages below 2.2.4 Describe the intrinsic and extrinsic regulation of heart rate and the sequence of excitation of the heart muscle. List the 5 steps below of intrinsic and extrinsic regulation of heart rate and the sequence of excitation of the heart muscle. (SEE KEYNOTE) 1. 2. 3. 4. 5. IB Sports, Exercise and Health Science Topic 2: Exercise Physiology: Cardiovascular System Past Paper Question 1. How is breathing rate regulated by the body to meet the increasing demands of exercise during a game of netball? Answer Increased carbon dioxide/lactic acid/acidity. Detected by chemoreceptors/baroreceptors/ mechanoreceptors/proprioceptors/ thermoreceptors. In carotid arteries/aortic arch. Nerve impulses to respiratory centre/medulla. Nerve impulses to breathing muscles/diaphragm/intercostal muscles. Deeper and faster breathing IB Sports, Exercise and Health Science Topic 2: Exercise Physiology: Cardiovascular System 2.2.6 Describe the relationship between heart rate, cardiac output and stroke volume at rest and during exercise Cardiac Output: Define the following key terms. Term Definition (including formula) Pulmonary circulation Part of the circulatory system that carries blood between the heart and lungs. Systemic circulation Part of the circulatory system that carries blood between the heart and the body. Unit Symb ol l/min Q ml SV Blood pumped per minute Cardiac output Blood pumped per beat Stroke volume Individual Activity Show your working to calculate your personal cardiac output in the space below IB Sports, Exercise and Health Science Topic 2: Exercise Physiology: Cardiovascular System Investigation 2 Class Activity Aim: To investigate the difference in stroke volume between males and females. Hypothesis Materials Stopwatch Method 1. Take your resting HR by finding your pulse and recording over 15 seconds then multiplying by four. 2. The average Q for a person is 5 litres per minute – using this information – calculate you stroke volume and enter the data into the data table. 3. Note down the rest of the classes results…make sure you collect everyone’s! 4. Separate the class stroke volumes by male & female. 5. Calculate mean SV for the males and the females. Results: Name Gender Q (l/min) 5 5 5 5 5 5 5 5 HR (bpm) SV (l) IB Sports, Exercise and Health Science Topic 2: Exercise Physiology: Cardiovascular System Analysis 1. Is there a difference between males and females? If so, explain why. 2. What conclusions can you draw about the general fitness of males compared to females? 3. What conclusions can you draw about the general fitness of the class? Changes to Cardiac Output during Exercise Individual Activity – Types of Exercise Choose the correct words from the word bank below. There are more words than required. Sub-maximal exercise is the average method of working out; you are not working at your physiological maximum. Heart rate is measured in beats per minute and relates to submaximal exercise in that when you are exercising, your measured heart rate is not as fast as it could be. When you reach your maximum amount of work that you are physiologically capable of performing, your heart rate will plateau. Heart rate should respond in a linear fashion to physical activity; however, other factors such as your medical history and level of fitness may play a role. Slow exercise should increase the heart rate, but not bring it to its maximum. Word Bank Maximum increase beats per minute slow fast decrease plateau Linear IB Sports, Exercise and Health Science Topic 2: Exercise Physiology: Cardiovascular System 2.2.6 Describe the relationship between heart rate, cardiac output and stroke volume at rest and during exercise Stroke Volume Fill in the following sentences: Stroke Volume increase during exercise- why? Exercise places an increased demand on the cardiovascular system. Oxygen demand by the muscles increases sharply. Metabolic processes speed up and more waste is created. More nutrients are used and body temperature rises. At a linear rate to the speed/ intensity of the exercise (up to about 4060% of maximal intensity). Once 40-60% of maximum intensity is reached stroke volume reaches a plateau. Therefore stroke volume reaches it’s maximal during sub-maximal exercise. IB Sports, Exercise and Health Science Topic 2: Exercise Physiology: Cardiovascular System What causes stroke volume (and therefore Q) to increase? More blood is being returned to the heart – this is called Venous Return. Less blood left in heart; (End Diastolic Volume- EDV; the volume of blood in the right and/or left ventricle at end load. Increased Ventricular Contraction (aka Diastolic Filling) occurs, this increases the pressure and stretches the walls of the ventricles, which means that a more forceful contraction is produced. This is known as Starling’s Law. (more stretch = more forceful contraction). During maximal exercise the cardiac output will need to be increased, however stroke volume has already reached its maximum. Heart rate increases. As a result of this stroke volume starts to decrease - the increase in HR means that there is not as much time for the ventricles to fill up with blood, so there is less to eject (causes the HR to increase even more). IB Sports, Exercise and Health Science Topic 2: Exercise Physiology: Cardiovascular System Heart Rate Before exercise Increases above resting HR before exercise has begun – known as anticipatory response, is as a result of the release of adrenalin which stimulates the SA node. Sub-maximal Exercise Plateaus during sub-maximal exercise, called steady state exercise, means that the oxygen demand is being met. Maximal Exercise Heart Rate increases dramatically once exercise starts, continues to increase as Stroke Volume & Cardiac Output increases to meet the oxygen demand. IB Sports, Exercise and Health Science Topic 2: Exercise Physiology: Cardiovascular System Heart Rate decreases as exercise intensity decreases. After Exercise After exercise – heart rate decreases dramatically, then gradually decreases. Cardiac Output Increases directly in line with intensity from resting up to maximum. Plateaus during sub maximal exercise. IB Sports, Exercise and Health Science Topic 2: Exercise Physiology: Cardiovascular System Data Analysis of Cardiac Output The table below shows the cardiovascular responses during dynamic wholebody exercise for 2 adult males of similar age (20 years old) and size (1.8m, 70kg). One of the individuals is sedentary and the other one is a well- trained endurance athlete. The data reflects 3 levels of exercise intensity: 1. Rest 2. Sub-maximal exercise (exercise at a fixed intensity) Measurement Intensity Rest -1 Sub-max. Heart rate (beats.min ) Max. Rest -1 Sub-max. Stroke volume (ml.beat ) Max. Rest -1 Sub-max. Cardiac output (L.min ) Max. Untrained adult male 75 110 197 60 85 120 4.6 9.4 19.7 Trained adult male 50 80 195 90 112 190 4.5 9.0 32.2 3. Maximal exercise (exercise to the point of exhaustion) 1. Evaluate the effect of training on the cardiovascular response to sub maximal and dynamic exercise. An untrained athlete has a higher heart rate and lower stroke volume. Trained adult: Higher stroke volume- larger heart therefore more blood being pushed around the body so there is more circulation’ efficiency in a trained athlete. 2. Aside from any differences in training status, predict any difference that you would expect if the data in the above table were compared to an adult female. IB Sports, Exercise and Health Science Topic 2: Exercise Physiology: Cardiovascular System Females- typically smaller, smaller heart and less muscle mass. Lower Oxygen carrying capacity. Lower aerobic capacity VO2 max. Sub-maximal cardiovascular responses are different in children and adults. Both boys and girls have a lower cardiac output than adults at a given absolute sub-maximal rate of work. This lower cardiac output is attributable to a lower stroke volume, which is partially compensated for by a higher heart rate. The table below shows the data from a study comparing cardiovascular responses to cycling and treadmill running in 7-9 year old children versus 18-26 year old adults. Exercise Cycle 60W Run 3 mph Cardiac output (L.min )-1 Child Adult 9.4 12.4 6.7 12.3 Stroke volume (ml.beat-1 Child Adult 61.9 126.8 57.3 135.7 Heart rate (beats.min-1) Child Adult 153.1 97.8 11.6 92.0 1. Compare the cardiac output, stroke volume and heart rate between the child and the adult. Sub-maximal cardiovascular responses are different in children and adults. Both boys and girls have a lower cardiac output than adults at a given absolute submaximal rate of work. This lower cardiac output is attributable to a lower stroke volume, which is partially compensated for by a higher heart rate. See page 43 SEHS course companion 2. Explain the cardiac output, stroke volume and heart rate between the child and the adult. Differences in sub maximal cardiovascular responses between children and adults are related to the smaller hearts and a smaller amount of muscle doing a given rate of work in children. N.B. Child has larger surface area to volume ratio than adult, (because is smaller): so child has more heat loss per unit area, so needs a higher metabolic rate than an adult to maintain the same body temperature. IB Sports, Exercise and Health Science Topic 2: Exercise Physiology: Cardiovascular System Child also has an additional metabolic load because it is growing, Adaptations of the Heart to Exercise Heart Size Physiological Adaptation The muscular walls of the heart increase in thickness, particularly in the left ventricle, providing a more powerful contraction. Stroke Volume (SV) Resting Heart Rate (RHR) The left ventricles internal dimensions increase as a result of increased ventricular filling. The increase in size of the heart enables the left ventricle to stretch more and thus fill with more blood. The increase in muscle wall thickness also increases the contractility resulting in increased stroke volume at rest and during exercise, increasing blood supply to the body. As cardiac output at rest remains constant the increase in stroke volume is accompanied by a corresponding decrease in heart rate. Cardiac output increases significantly during maximal exercise effort due to the increase in SV. This results in greater oxygen supply, waste Cardiac Output (Q) removal and hence improved endurance performance. People with blood pressure in the ‘normal’ ranges experience little change in BP at rest or with exercise; however hypertensive people find that their BP’s reduce towards normal as they Blood Pressure (BP) do more exercise. This is due to a reduction in total peripheral resistance within the artery, and improved condition and elasticity of the smooth muscle in the blood vessel walls. http://www.ptdirect.com/training-design/anatomy-and-physiology/adaptationsto-exercise/chronic-cardiovascular-adaptations-to-exercise IB Sports, Exercise and Health Science Topic 2: Exercise Physiology: Cardiovascular System Past Paper Questions 1. Explain how it is possible for a trained performer and an untrained performer to have the same cardiac output for a given workload. (4) Different sized hearts/hypertrophy -trained bigger; Different stroke volumes - trained bigger; Different heart rates - untrained higher; Can only occur at sub maximal workloads; At higher workloads untrained will not be able to increase their heart rate sufficiently; Different physiques/size/mass -untrained bigger. 2. Describe the relationship between heart rate, stroke volume and cardiac output during rest, sub-maximal rowing and maximal rowing. (2) HR is the number of times the heart beats per minute SV is the amount of blood pumped out by the left ventricle in each contraction. Q is found by multiplying the heart rate (bpm) by the stroke volume (ml of blood/beat) HR increases in direct proportion to the increase in exercise intensity Initially Q increases as a result of both increase in HR and SV Maximal SV is achieved during sub-maximal work Any increase in Q output during maximal exercise is due solely to increase in HR. 3. Briefly explain the terms ‘cardiac output’ and ‘stroke volume’, and the relationship between them. (3 marks) Cardiac output - ‘the volume of blood pumped from heart/ ventricle in one minute; Stroke volume - ‘the volume of blood pumped from the heart/ ventricle in IB Sports, Exercise and Health Science Topic 2: Exercise Physiology: Cardiovascular System one beat Cardiac output = stroke volume x heart rate/Q = SV x HR Investigation 3 Calculating Maximal Heart Rate for Training To make sure you are getting the most out of your workouts, you should exercise within what is called your “Training Heart Rate Zone”. This activity will teach you how to calculate for that zone/range, which is 60-80% of your maximum heart rate. 60% = low intensity, 70% = moderate intensity, 80% = high intensity Part I- Calculate your HR Zones using both formulas Use the Maximum HR Formula to get the HR zones: Calculate your Resting Heart Rate (RHR) The RHR should be taken first thing on 3 consecutive mornings upon waking and before getting out of bed. Calculate your estimated Maximal Heart Rate (MHR) o (220 – Age = MHR) IB Sports, Exercise and Health Science Topic 2: Exercise Physiology: Cardiovascular System Calculate your Target Heart Rate Zone (THRZ) by multiplying by 65% and 80% of your MHR to get your ‘low’ end and ‘high’ end threshold. (MHR X 0.65 = 65% of MHR) and (MHR X 0.80 = 80% of MHR) Use the Karvonen Formula to get the HR zones: (This is a much harder way to get your zones) Ideally, you resting heart rate will be what you are first thing in the morning waking up. The Karvonen heart rate method 220- (Age –Resting HR) x Intensity level + Resting HR 220 (max heart rate) 50% = Lower range of exercise intensity 85% = Upper range of exercise intensity 1. 220 – 17 = 203 2. (203 – 66) x .50) + 66 = 135 bpm – lower range 3. (203 – 66) x .85) + 66 = 182 bpm – upper range Gives you a nice range of where you want to be with your exercise level. For athletes they may want to go slightly higher than 85%. Part II- Perform the following activities and write down your HR response Do Heart Rate Lab (one with coke) IB Sports, Exercise and Health Science Topic 2: Exercise Physiology: Cardiovascular System 2.2.9 Systolic and diastolic blood pressure Read the passage below and highlight key terms and ideas Blood flow changes dramatically once exercise commences. At rest, only 1520% of cardiac output is directed to skeletal muscle (the majority of it goes to the liver and the kidneys. Blood is redirected to areas where it is needed most. This is known as shunting or accommodation. When exercising, the increased metabolic activity increases the concentration of carbon dioxide and lactic acid in the blood. This is detected by chemoreceptors and sympathetic nerves stimulate the blood vessel size to change shape. Vasodilation will then allow a greater blood flow, bringing the much needed oxygen and flushing away the harmful waste products of metabolism. The redistribution of blood is controlled primarily by the vasoconstriction and vasodilation of arterioles. They react to chemical changes of the local tissue. For example, vasodilation will occur when arterioles sense a decrease in oxygen concentration or an increase in acidity due to higher CO2 and lactic acid concentrations. Sympathetic nerves also play a major role in redistributing blood from one area of the body to another. The smooth muscle layer (tunica media) of the blood vessels is controlled by the sympathetic nervous system, and remains in a state of slight contraction. By increasing sympathetic stimulation, vasoconstriction occurs and blood flow is restricted and redistributed to areas of greater need. When stimulation by sympathetic nerves decreases, vasodilation is allowed which will increase blood flow to that body part. Define the terms systolic and diastolic blood pressure IB Sports, Exercise and Health Science Topic 2: Exercise Physiology: Cardiovascular System Function Diastolic Systolic The force exerted by blood on arterial walls during ventricular relaxation. The force exterted by blood on arterial walls during ventricular contraction. Define: Vasodilation Vasoconstriction Blood Pressure Blood Vessels dilate Blood Vessels become narrow IB Sports, Exercise and Health Science Topic 2: Exercise Physiology: Cardiovascular System Measured in blood vessels (artery) Blood pressure is the measurement of force applied to artery walls. Narrower vessels (vasoconstriction) Wider vessels (vasodilation) 2.2.10 Analyse systolic and diastolic blood pressure data at rest and during exercise Complete the table below using the word bank below: Describe Explain Skeletal muscle – massive increase in blood flow (26 fold) to working muscle. At maximum effort muscle takes 88% of blood flow Coronary vessels – blood vessels that serve cardiac muscle (which needs oxygen and respiratory substrates). Nearly a 5 fold increase in blood flow during exercise. Skin – small increase in blood flow to the skin during exercise. Kidneys – significant reduction in blood flow during exercise. Liver & gut - significant reduction in blood flow during exercise Brain – blood flow is maintained at the same level during exercise Whole body – the volume of blood pumped per minute is the same measure as cardiac output The force exerted by blood on arterial walls during ventricular relaxation. As a working muscle, the heart needs its share of oxygen. When the heart rate increases, it needs more oxygen to make energy and to remove CO2. Temperature regulation. Vasodilation of arterioles increases flow rate to the skin. We go red and lose some heat through evaporation of sweat. Non-essential function during exercise. Non-essential function during exercise. The brain needs a constant supply of oxygen to function properly. Exercise makes no change to this demand. Increased cardiac output is a response to increased work rate and the associated demand for energy. Cardiac output is raised by increasing heart rate and stroke volume. IB Sports, Exercise and Health Science 2.2.11 Topic 2: Exercise Physiology: Cardiovascular System How does Systolic and diastolic blood pressure respond to dynamic and static exercise. IB Sports, Exercise and Health Science Topic 2: Exercise Physiology: Cardiovascular System Complete the paragraphs below using terms for the word bank provided The heart muscle contracts in two stages to squeeze blood out of the heart. This is known as systole. In the first stage, the upper chambers (atria) contract at the same time, pushing blood down into the lower chambers (ventricles). Blood is pumped from the right atrium down into the right ventricle and from the left atrium down into the left ventricle. In the second stage, the lower chambers contract to push this blood out of the heart to either the body via your main artery (aorta) or to the lungs to pick up oxygen. IB Sports, Exercise and Health Science Topic 2: Exercise Physiology: Cardiovascular System The heart then relaxes – known as diastole. Blood fills up the heart again, and the whole process, which takes a fraction of a second, is repeated. (i) Blood pressure is the measurement of force applied to artery walls. It increases during exercise because more blood is pumped around the body, increasing pressure in the blood vessels. (ii) Systolic: The blood pressure when the heart is contracting. It is specifically the maximum arterial pressure during contraction of the left ventricle of the heart. The time at which ventricular contraction occurs is called systole. In a blood pressure reading, the systolic pressure is typically the first number recorded. For example, with a blood pressure of 120/80 ("120 over 80"), the systolic pressure is 120. By "120" is meant 120 mm Hg (millimeters of mercury). (iii) The diastolic pressure is specifically the minimum arterial pressure during relaxation and dilatation of the ventricles of the heart when the ventricles fill with blood. In a blood pressure reading, the diastolic pressure is typically the second number recorded. For example, with a blood pressure of 120/80 ("120 over 80"), the diastolic pressure is 80. By "80" is meant 80 mm Hg (millimeters of mercury). Right atrium Artery Lower chambers Systole Upper chambers Left ventricle Oxygen Blood vessels Diastole Systolic measurement of force contracting ventricular Diastolic Ventricles Second first 2.2.11: Data analysis questions Activity Rest Diastolic pressure (mmHg) 75 Systolic Pressure (mmHg) 11 6 IB Sports, Exercise and Health Science Topic 2: Exercise Physiology: Cardiovascular System 80kg healthy male 100 kg unhealthy male Running Lifting 80 150 Rest 95 18 0 24 0 15 The table above presents data for a healthy trained 80kg male at rest and performing two different actions (running fast, a dynamic activity, trying to lift a very heavy object, static but very high forces), as well as resting data for another untrained and unhealthy individual. Answer the following questions 1. Compare the effect of dynamic exercise and static exercise on blood pressure? See keynote Answer 2. Explain why one is higher than the other? See keynote Answer 3. Describe the difference between the two participants at rest. Answer Effects of Exercise As you begin to exercise, your body produces more carbon dioxide, which causes you to breathe more quickly. Your heart responds by pumping harder to produce more oxygen. Next, your blood pressure increases and your arteries widen, which brings more blood to your heart. This action causes the heart to beat even more. An unfit person has a higher heart rate than a fit person because his body works harder during this process. Often, the arteries are clogged and the blood pressure is high, forcing the heart to beat faster than normal. http://www.livestrong.com/article/370950-what-is-an-unfit-persons-heart-rate-while-exercising/ 2.2.12: Redistribution of blood during exercise IB Sports, Exercise and Health Science Topic 2: Exercise Physiology: Cardiovascular System Factors affecting blood pressure Factor Cardiovascular centre Smoking Diet Adrenaline Increase in blood viscosity 2.2.12 Explanation Diameter of blood vessels controlled by stimulation of sympathetic and parasympathetic nerves. Nicotine causes vasoconstriction Build up of fatty deposits in vessels High fat diet leads to build up of fatty deposits in blood vessels Causes selective vasoconstriction & vasodilation Excess water loss (sweating/excessive urination) Compare the distribution of blood at rest and during exercise Compare the values. IB Sports, Exercise and Health Science Topic 2: Exercise Physiology: Cardiovascular System 2.2.8: Cardiovascular Drift We used to think that exercising at a steady level led to the body reaching a steady state, where the heart rate remained the same. However, research has shown that it does not stay the same but instead increases slowly. This is Cardiovascular drift. It is characterized by a progressive decrease in stroke volume and arterial blood pressure, together with a progressive rise in heart rate. It generally occurs during prolonged exercise in a warm environment despite the intensity of the exercise remaining the same. It is suggested that cardiovascular drift occurs because when we sweat a portion of the lost fluid volume comes from the plasma volume. The decrease in plasma volume reduces venous return and stroke volume.An increase of body temperature results in a lower venous return to the heart, a small decrease in blood volume from sweating. A reduction in stroke volume causes the heart rate to increase to maintain cardiac output. If CVD did not occur, a person would have to lower his/her intensity. Katch, McArdle, Katch (2011) IB Sports, Exercise and Health Science Topic 2: Exercise Physiology: Cardiovascular System In summary: Explanation for Cardiac Drift Continuous exercise – decrease in volume of blood plasma. Fluid seeps into surrounding tissues and cells Fluid lost to sweating If athletes fail to re-hydrate, can further reduce the volume of blood returning to heart Reduces blood volume and hence reduces stroke volume. Therefore reduced venous return to the heart. …..According to Starling’s Law IB Sports, Exercise and Health Science Topic 2: Exercise Physiology: Cardiovascular System Cardiac output (Q) needs to be kept constant Q = SV x HR - if SV decreases, then HR must increase. Hence there is a need for increase in heart rate during steady state exercise to maintain redistribution of blood flow. 2.2.13 Describe the cardiovascular adaptations resulting from aerobic training Please read and highlight the following, which you think is important. 2.2.13 Cardiovascular adaptations resulting from endurance exercises Acute cardiovascular (circulatory system) responses to exercise 1. When you begin to exercise, your HR increases to to the working muscles. If you exercise at a constant pace, your HR will level off & remain constant until you go faster or stop. This is ‘steady state’, and indicates that the muscles are receiving enough blood & O2 to keep working at that pace. (O2 supply = O2 demand). 2. Stroke volume is the amount of blood pumped out of the L ventricle with each heart beat (contraction). Your SV depends on the size of your left ventricle, which is determined by a combination of genetics & training. When you begin to exercise, your heart muscle contracts more forcefully to increase blood (& hence O2 ) supply to your muscles. This causes a more complete emptying of your ventricles, so SV increases. 3. Cardiac Output is the amount of blood pumped out of the heart’s left ventricle in 1 minute. 4. CO = SV x HR IB Sports, Exercise and Health Science Topic 2: Exercise Physiology: Cardiovascular System When you exercise, your Cardiac Output increases in an effort to increase the blood supply (& hence O2 delivery) to the working muscles. 5. Blood Pressure is a measure of the pressure produced by the blood being pumped into the arteries. Systolic B.P. - pressure as the LV ejects the blood into the aorta during heart contraction. Diastolic B.P. - pressure in the arteries during relaxation of the heart. Blood Pressure increase’s during exercise because SV, HR & CO all increase, more blood is pumped into the arteries more quickly. Blood Pressure is the measurement of force applied to artery walls. During exercise, blood flow to the working muscles increases because of increased Cardiac Output & a greater distribution of blood away from nonworking areas to active muscles. 80-85% of Cardiac Output goes to working muscles, because muscle capillaries dilate to allow more blood flow to the muscles called vasodilation. Blood flow to kidneys, stomach & intestines ¯ decreases because the capillaries constrict - called vasoconstriction. Blood flow to the lungs increases, as the right ventricle increases its activity during exercise. To allow for this increased blood flow to the muscles, there must be an accompanying increase in venous return (blood flow back to heart through the veins). IB Sports, Exercise and Health Science Topic 2: Exercise Physiology: Cardiovascular System Due to an increase in sweating, the blood plasma volume decreases during strenuous exercise, especially in hot weather. Acute Muscular Responses to Exercise contraction rate recruitment of muscle fibres & motor units to produce more force muscle temperature Depletion of fuel stores used to produce energy for contractions blood flow to muscles (blood vessels dilate) O2 attraction at the muscle During exercise & recovery, more O2 must be delivered from the lungs to the working muscles, & excess O2 must be removed from the working muscles. IB Sports, Exercise and Health Science Topic 2: Exercise Physiology: Cardiovascular System Acute respiratory responses to exercise During exercise & recovery, more O2 must be delivered from the lungs to the working muscles, & excess O2 must be removed from the working muscles. respiratory rate tidal volume ventilation lung diffusion O2 uptake, or volume of O2 consumed Respiratory rate At rest, you breathe about 12-15 times each minute. When you begin to exercise, the CO2 level in the blood ’s, because CO2 is a waste product of energy production. This triggers the respiratory centre in your brain & you breathe faster. tidal volume- is the size of each breath taken and during heavy exercise, tidal volume can increase to 2.5L per breath as the body tried to increase the oxygen supply to the blood. ventilation- the amount of air breathed in 1 minute dependent on the number of breaths and the size of each breath. lung diffusion- increase in in O2 diffucion from the alveoli to the blood because of a massive increase in blood flow to the lungs and dilation of the capillaries surrounding the alveoli. O2 uptake, or volume of O2 consumed- When you begin to exercise, your VO2 increase’s as your body absorbs more O2 & uses it to produce more aerobic energy. IB Sports, Exercise and Health Science Topic 2: Exercise Physiology: Cardiovascular System Chronic Training Adaptations When we discuss chronic adaptations to training, we are assuming that training has been occurring for a minimum of 6-8 weeks, training at least 3 sessions per week. 2.2.14 Explain maximal oxygen consumption. VO2max Maximum oxygen consumption, also referred to as VO2max. Fitness can be measured by the volume of oxygen you can consume while exercising at your maximum capacity. Maximal Oxygen Consumption is sometimes referred to as maximal aerobic power or aerobic capacity. Those who are ‘fitter’ have higher VO2 max values and can exercise more intensely than those who are not as well conditioned. IB Sports, Exercise and Health Science Topic 2: Exercise Physiology: Cardiovascular System 2.2.14: Definition - VO2 Max IB: VO2 max is the maximum amount of oxygen in milliliters that an individual can utilize whilst performing dynamic exercise. Q1. Why is VO2 expressed as mL kg-1 per minutes? Answer VO2 max is directly related to body mass; Expressing relative to body mass allows comparison of individual of different sizes Q2: State the different factors that affect VO2 max/aerobic capacity? Answer Specific exercise Level of/type of fitness/RBC count/health/social habits Whole body movements Training Zones Altitude training Age Gender/Sex Asthma Body composition/Body fat Blood doping (illegal and dangerous) IB Sports, Exercise and Health Science Topic 2: Exercise Physiology: Cardiovascular System Read Below Training can have the effect of making the CVR system more efficient and improving your Vo2 max scores. The effects depend on the type of training, its intensity and its duration. Recent research suggests that you can increase your VO2 max by working out at an intensity that raises your heart rate to between 65 and 85% of its maximum for at least 20 minutes three to five times a week. Interval training has also been indentified as an effective training method (high intensity + rest periods) with your HR recovering to at least 120bpm. Effects can include improved or increased ability: o to metabolise fat o of the blood to ‘pick up’ and transport oxygen from the lungs o of the muscles to use oxygen o to remove waste products o to increase VO2 max o to work at a higher percentage of VO2 max o to recover, both during and after exercise o to regulate body temperature o to work faster/harder for longer o to reduce risk of coronary heart disease/diabetes/health disorders. Past Exam Q: How can specific training increase an athlete’s VO2 Max? o Improve the efficiency of the CV system o Hypertrophy of the heart = greater quantity of oxygenated blood pumped per beat o Marginal increases in surface area of the alveoli/lung capacity o Increased pulmonary diffusion o Improve the ability of the muscles used to utilize oxygen o More myoglobin and more and bigger mitochondria in the muscles o Increased rate of diffusion at the tissue o Increased quantity of haemoglobin in the blood o Improve the efficiency of the muscles used to generate energy o Increased vascularisation of the heart/muscles (the development of blood vessels) o IB Sports, Exercise and Health Science 2.2.15 Topic 2: Exercise Physiology: Cardiovascular System Discuss the variability of maximal oxygen consumption in selected groups Question: List the factors that VO2 max depends on. IB Sports, Exercise and Health Science Topic 2: Exercise Physiology: Cardiovascular System Factor Heredity Age Sex Body size and composition Explanation Genetic effect is currently estimated at approximately 20-30% for VO2 max, 50% for maximum heart rate, and 70% for physical working capacity. Absolute values for girls and boys are similar until age 12. At age 14 VO2 max value for boys 25%> and by age 16, the difference exceeds 50%. After age 25 its all down-hill (VO2 max declines at a rate of 1% per year after age 25). BUT one’s habitual level of physical activity has far more influence on aerobic capacity than age! Even among trained endurance athletes, the sex difference for VO max = 15-20% mainly due to differences in: (1) Body Composition and (2) Haemoglobin. An estimated 69% of the differences in VO2 max scores among individuals can be explained by variations in body mass. Mode of exercise Highest values are generally found during treadmill exercise, lowest on bicycle ergometer test; specificity is very important. Muscle fiber type Slow oxidative fibers - highest oxygen consumption. Altitude Low partial pressure of O2 in the atmosphere. Lower partial pressure of O2 in the arterial blood. Lower haemoglobin saturation Higher temperature - higher oxygen consumption. Temperature IB Sports, Exercise and Health Science 2.2.15: Topic 2: Exercise Physiology: Cardiovascular System Discuss the variability (data) of maximal oxygen consumption (Vo2) in the different groups above (6) Untrained v Trained Young v Old Male v female You will need to also look at (1) heart rate levels, (2) SV output, and (3) cardiac output to gain extra discussion points and apply to the above groups (2.2.7) Mean value of VO2 max Non - trained Endurance Trained *Male (46- 55 Yr old) *Female (46-55 Yr old) Male (40- 49 Yr old) Female (40-49 Yr old) *Male (36-45 Yr old) *Female (36-45 Yr old) Male (40 Yr old) Female (40 Yr old) 25-28 mls/kg/min 20-24 mls/kg/min 38-40 mls/kg/min 31-32 mls/kg/min 51 mls/kg/min 45 mls/kg/min 3.5 litres/minute (3,500ml) 2.7 litres/minute (2,700ml) Endurance Cyclist/Runners - 75 mls/kg/min 42-46 mls/kg/min Young Person *Male (18-25 Yr old) *Female (18-25 Yr old) Male (20-29 Yr old) Female (20-29 Yr old) 38-44 mls/kg/min 42-49 mls/kg/min 35-37 mls/kg/min IB Sports, Exercise and Health Science Topic 2: Exercise Physiology: Cardiovascular System Professional Footballers Elite Footballers 2.2.16: 50 mls/kg/min 60 mls/kg/min Outline the different tests/modes of exercise which can test Maximum oxygen consumption (VO2max )? Key point is that data generated from the different tests/exercise is reflected by the quantity of activated muscle mass. Answer Multistage fitness test Gas analysis Test Treadmill Test Bench Step Test Bicycle Test Arm crank exercise (cycling arms, similar to bike pedaling) IB Sports, Exercise and Health Science Topic 2: Exercise Physiology: Cardiovascular System Investigation 2 Practical Activity – Bleep Test (http://www.topendsports.com/testing/beepcalc.htm) What is tested: VO2 max- aerobic fitness level Equipment needed: Stereo; bleep test CD; cones Purpose of test: To estimate maximal oxygen uptake and utilization (VO2) by administering a progressive shuttle run test. Procedure & Measurement 1. Measure a distance of 20 metres and mark with two cones. 2. The client should perform a short warm including CV and stretching. 3. Start the CD, the participants will run 20 metres to the furthest cone when the first three bleeps sound. 4. When the bleep sounds on the CD the participant turns around to run back. IB Sports, Exercise and Health Science Topic 2: Exercise Physiology: Cardiovascular System 5. The client must reach the line before the third bleep 6. The participants continue to run between the cones and the time between the bleeps becomes shorter- hence the participants need to run faster to reach the cones. 7. If the participant fails to get to the other end before the bleep on 3 consecutive occasions then they are out.(2 chances). 8. Record the level at which the participant stopped the test. 9. Compare to VO2 max tables. Notes: As this is a maximal test, certain precautions should be taken. Participants should have no apparent health problems. Stage Level 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 IB Sports, Exercise and Health Science Topic 2: Exercise Physiology: Cardiovascular System * * mark off the stage you reached, for each level, the last box filled in is your score** http://www.nogometnitrening.com/