Taking pulses and calculating blood flow

• Multicellular organisms require transport systems to supply their cells and remove waste products.
• In humans, one of the functions of the circulatory system is to transport substances.
• The heart is a crucial part of the circulatory system.
• Circulation is controlled by the heart rate.
• Blood vessels are a part of the circulatory system.
• White blood cells are a part of the circulatory system.
• Development of cardiovascular disease can be evaluated.
• Ways of treating cardiovascular disease include heart transplants.
• Heart transplants are evaluated for their effectiveness.
• Taking pulses and calculating blood flows is a way of checking heart rate.
• The simplest way of checking heart rate is to measure your pulse.
• The pulse can be felt in locations where an artery passes over a solid structure, such as bone.
• Locations where the pulse can be felt include wrist, neck and upper arm.
• The pulse rate is expressed in beats per minute.
• To measure your pulse rate, count the number of beats in a set period of time, such as 30 seconds or a minute.
• In healthy people, generally, the lower the resting pulse rate, the fitter they are.
• Pulse rates increase during and after exercise, as more oxygen must be provided to the muscles and carbon dioxide removed.
• Flow rates of blood can be measured using scanning techniques such as MRI.
• The blood flow from the heart is called cardiac output.
• Cardiac output is the amount of blood pumped by the heart in one minute.
• Stroke volume is the volume of blood pumped out of the heart per beat.
• Cardiac output in cm3 per minute = heart rate in beats per minute × stroke volume in cm3 per beat.
• An increase in heart rate or stroke volume will increase cardiac output.
• If a person has a resting heart rate of 70 beats per minute and a resting stroke volume of 75 cm3 per beat, the cardiac output for this person at rest is: Cardiac output in cm3 per minute = 70 × 75 = 5250 cm3 per minute.
• If an athlete's maximum heart rate is 130 beats per minute and stroke volume is 150 cm3, their cardiac output in dm3 is: Cardiac output in cm3 per minute = 130 × 150 = 19 500 cm3 per minute = 19.5 dm3 per minute.