D4 - Effects on the cardiovascular system

• heightened levels of oxygen and nutrients

• when the heart starts to beat faster before any physical activity has occurred

• to prepare the body for the demands it will face • sympathetic nervous system will initiate increased heart rate based on chemo receptors in the blood • send signals to SA node to increase the ‘rhythm’ of the heart ready for exercise (release of adrenaline) • largest anticipatory rise effect can be seen in short sprints

• medulla receives signals from chemo receptors and sympathetic nervous system identifying the need for more oxygen • increase rate at which the heart beats • pumping strength increases due to messages from the medulla • distribution of blood flow is altered in proportion with the amount/ intensity of exercise undertaken

• the amount of blood pumped out of the left ventricle to the body in one minute • during activity in sport/exercise the amount of oxygenated blood required increases, therefore more blood is pumped at a faster rate • stroke volume does not increase unless taking part in high intensity exercise, there is only a slight increase then • major change in cardiac output come from a significant increase in heart rate • maximum possible cardiac output is affected by age (due to having lower maximum heart rate) • reliant on ‘venous return’

cardiac output = heart beat x stroke volume - heart beat = amount of times the heart beats per minute - stroke volume = amount of blood pumped out of the heart per beat

• stroke volume is dependent on the amount of blood sent back to the heart (venous return) • the lower the venous return, the lower potential stroke volume

• during exercise systolic pressure increases but diastolic pressure either stays the same or decreases • increased demands of muscles for oxygen • heart is working harder (pumping blood faster) • diastolic drops/ stays the same, as the vessels vasodilate to allow more blood to pass through them • readings will show systolic pressure over diastolic recording mm-Hg (millimeters of mercury)

• the pressure of the blood against the walls of the arteries • resulting in two forces; systolic and diastolic

• the pressure exerted on your artery walls when your heart contracts and forced blood out of the heart and into your body

• the pressure on the blood vessel walls when the heart is relaxed between beats and is filling with blood

• muscles require more oxygen when exercising • body redirects blood flow to these areas • blood is channeled to certain areas of the body using vasodilation and vasoconstriction of blood vessels • certain areas of the body will see a reduction in blood flow

• anticipatory rise • increased heart rate • increased cardiac output • increased blood pressure • redistribution of blood flow

• the enlargement of your heart over a long period of time (myocardium) • training leads to increased muscle mass of the cardiac muscles, specifically walls of the left ventricle (increases ‘strength potential’)

• the amount of blood ejected (pumped) out of the heart in one beat (one stroke) • more oxygen can be transported around the body is one beat • performers resting stroke volume is significantly higher after prolonged endurance training programmes (training for years) • heart can pump more blood per beat, increases cardiac output • blood flow largely increased for delivery of more nutrients and oxygen to working muscles • lower venous return = lower stroke volume

• due to cardiac hypertrophy & increasing in resting/ exercising stoke volumes the heart does not need to beat as many times to get the same level of blood/oxygen to working muscles • heart rate decreases due to high efficiency

• exercise causes blood pressure to increase for a short time • after exercise, blood pressure will gradually return back to normal • quicker the body is able to return back to it’s original state the fitter the person • regular exercise can contribute to lowering resting blood pressure

• hypertension • prescribed exercise to these people to reduce blood pressure • values for these people are 140/90 - 190/100 mm-Hg

• measured of how much your heart rate falls the first minute after exercise • fitter= quicker reduction in heart rate in recovery time • due to cardio-respiratory system being able to respond to increasing demands on the body

• increase in density of capillaries (more of them) • increase in number and size in muscles & alveoli • leads to increased blood flow, allowing for more efficient transport of blood (oxygen and nutrients)

• represents the amount of blood circulating in your body • increases as a result of training = everyone’s different • increases as a result of capillarisation • means you body can deliver more oxygen to your working muscles • body will be able to regulate temperature more efficiently during exercise

• cardiac hypertrophy • increasing in resting and exercising stroke volume • decreasing in resting heart rate • reduction in resting blood pressure • decreased heart rate recovery time • capillarisation of skeletal muscle and alveoli • increase in blood volume

• sudden arrhythmic death syndrome (SADS) • high and low blood pressure • hyperthermia/ hypothermia

• a genetic heart condition that can cause sudden death in young, healthy people • person may have no disease affecting the structure of the heart • hearts normal rhythm is disrupted and the heart can stop beating and not adapt to this change