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Learn about Cardiac Output, Resting Pulse, and Measuring Blood Pressure in this informative lesson. Understand how heart rate and stroke volume affect Cardiac Output calculation and the impact of activity level on pulse rate. Discover the significance of Blood Pressure measurement, its ranges, and the risks associated with hypertension.
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Physiology, Health & Exercise Lesson 4 Cardiac Output Resting Pulse Measuring Blood Pressure
Puzzle • If you have three oranges and you take away two, how many will you have?
Puzzle- answer • Two. The two you took.
Cardiac Output (CO) • Volume of blood pumped by each ventricle per minute • Related to • heart rate (HR) and • stroke volume (SV) • Measured in litres per minute CO = HR x SV
Cardiac Output (CO) Example • heart rate (HR) = 72bpm • stroke volume (SV) = 70ml • What is the CO? • CO = 72 x 70 = 5040ml/min • = 5.04l/min • As activity level increases CO also increases
Average Resting pulse • 60-100bpm • Fitter people have a lower resting pulse • E.g. very fit athletes--> 30-40bpm • Resting pulse decreases with age • As activity level increases pulse (& Heart rate) increases
Activity & CO Calculate the CO in each case
Activity & CO • What is the effect on the following as the work load increases • Heart rate? • Stroke volume? • What is the CO principally due to?
Blood Pressure (b.p.) • Measure of force of blood against the walls of the arteries • B.p. highest during systolic phase of cardiac cycle • B.p. lowest during diastolic phase of cardiac cycle • Measured using a sphygmomanometer and stethoscope
Blood Pressure (b.p.) • Measured as raising a column of mercury so units mm Hg. • Reported as 2 numbers • So if systolic is 140 mm Hg & diastolic is 85 mm Hg then: Systolic Diastolic 140/85
Blood Pressure (b.p.) • Systolic b.p. changes during exercise and can reach 200mg Hg • Diastolic b.p. remains approx constant • Measured using a sphygmomanometer and stethoscope
Blood Pressure (b.p.) • First- reading- Systole -when blood spurts through an artery as the pressure in the artery exceeds the pressure in the cuff • Second reading- Diastole- more air released from cuff- initially sounds are louder, then muffle and disappear as blood flows continuously through the artery • measuring blood pressure
Blood Pressure (b.p.) • Average healthy person range of values: 140- 100 90-60
Blood Pressure (b.p.)- changes • B.p. increases as age increases • B.p. decreases as age decreases • B.p. increases as heart is overworking • Elevated b.p.- hypertension one of the most common factors in the development of CVD (cardiovascular disease)
Raised Blood Pressure (b.p.) • Elevated b.p.- increases chance of atherosclerosis occurring • Hypertension- symptom less in early stages • however if it continues it puts an excessive strain on the heart & if untreated will cause heart failure