Circulation and Immunity Cardiovascular System The system consisting of the heart, blood vessels and blood that circulates through the body. Cardiovascular System The human circulatory system performs four key functions. It transports and delivers oxygen and nutrients (e.g. minerals, vitamins, and glucose) to the body’s cells in exchange for carbon dioxide and wastes. It transports chemical messengers, such as hormones throughout the body. It distributes heat It defends against disease Cardiac Output Cardiac Output is the volume of blood pumped by the heart in one minute, which is equal to the product of stroke volume and heart rate. Average Values The average human male pumps out 70mL of blood per beat (60 mL for females) with an average resting heart rate is around 72 beats per minute. Example Question A typical human male has a stroke volume of 70 mL per beat and a resting heart rate of 72 beats per minute. A. Calculate the cardiac out put. Express your answer in litres per minute. B. Calculate the volume of blood that would be pumped in one day based upon the cardiac output. Example Question A typical human male has a stroke volume of 70 mL per beat and a resting heart rate of 72 beats per minute. A. Calculate the cardiac out put. Express your answer in litres per minute. Solution. Stroke volume = 70 mL/beat 70 mL x 1/1000mL = 0.070 L/beat Example Question A typical human male has a stroke volume of 70 mL per beat and a resting heart rate of 72 beats per minute. Solution. Cardiac output (stroke volume)x(heart rate) =(0.070 L/beat)x 72 (beats/min) = 5.04 L/min In one day 5.04 L/min x 1440 min/day = 7257.6 L = 7.3 x 103 L/day Heart Diagram Heart Diagram Blood Flow Blood Flow Blood Flow Blood Flow Heart Beat Diastole - the phase of the heart’s cycle where a chamber of the heart, either an atrium or a ventricle, relaxes and fills with blood. Semilunar valves closed - “dub” sound produced Systole - the phase of the heart’s cycle when the ventricles contract to eject blood from within the chamber. AV vales closed “lub” sound produced. Heart Beat Factors Affecting Heart Rate Emotions ie. Fear anxiety External temperature. Hotter = Higher HR Activity level. Age. Older you get the lower your max HR Fitness level. Medical conditions. Target Hear Rate for Exercise Your maximum heart rate is approximately 220 - your age. Target Heat Rates Personal Health Goal Maintain fitness level % of Max Heart Rate 50 - 60% Increase fat burning of 60 - 70% weight loss Increase cardiovascular 70 - 80% endurance