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GCSE Physical Education

GCSE Physical Education. The Circulatory System. At the end of this topic you should know the following…. The role and components of the circulatory system; The structure of the heart; How the circulatory system works; Definitions of… Heart rate, stroke volume, cardiac output;

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GCSE Physical Education

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  1. GCSE Physical Education The Circulatory System

  2. At the end of this topic you should know the following… • The role and components of the circulatory system; • The structure of the heart; • How the circulatory system works; • Definitions of… • Heart rate, stroke volume, cardiac output; • The roles and characteristics of the 3 types of blood vessels; • The functions of blood cells; • How the circulatory system is affected by exercise.

  3. The Circulatory System Components are… • The heart • Blood vessels • Blood Major functions include… • Transport of oxygen & carbon dioxide to & from muscles • Temperature regulation • Preventing infection

  4. The Heart • Use your textbooks to find out the correct answers to the following questions... • The heart is a special type of muscle called…? • Why is it special? • What is its main job? • Why is the heart often described as a ‘double pump’. • Approximately how big do you think the heart is?

  5. The Structure of the Heart Use your text books to label the different parts of the heart

  6. Group task • Organise yourselves into groups of 4-5 people. • You will need a sheet of A3 paper, a plastic wallet with labels inside, a pen/marker & paper glue. • Arrange the labels to accurately illustrate the structure of the heart, and the flow of blood around the cardiovascular system. • Link your labels together by drawing arrows between them where appropriate.

  7. When to use… Early to check KS3 science knowledge. Late to check KS4 science knowledge. Revision. Differentiation… Teacher decides on groups, or let students choose. Test answers with text book. Use more able student as observer. B&W and/or red & blue labels. Group task

  8. The Structure of the Heart

  9. The Circulatory System • Complete the worksheet. • If necessary, use your textbooks to help you. • Ask if you are unsure about any of the words.

  10. Blood vessels Blood vessels are needed to transport blood around the body • Arteries:carry oxygenated blood away from the heart to the organs & muscles • Veins:carry de-oxygenated blood back to the heart. This blood carries excess carbon dioxide and other waste products • Capillaries:the smallest blood vessels, which lie close to the muscle allowing oxygen and carbon dioxide to pass to & from the blood & the muscles

  11. Blood vessels – over to you • Use your textbooks to find out about the different blood vessels. • With a partner list the similarities and differences between arteries, veins and capillaries.

  12. Blood pressure • BP: pressure under which the blood travels as it is ejected from left ventricle • Blood vessel constriction increases BP; dilation reduces BP DIASTOLE: heart is relaxed, BP is reduced SYSTOLE: heart contracts, BP is increased BP during aerobic exercise • Systolic BP increases in direct proportion to increased exercise intensity • Diastolic BP changes little if any during endurance exercise, regardless of intensity

  13. Muscles help squeeze the blood through the veins back to the heart. • Note how valves work together.

  14. Blood – what is it?? • Blood accounts for ~ 8% of total body weight. • It is made up of cells & platelets, which are suspended in plasma. • There are 3 types of blood cells: • Red blood cells • White blood cells • Platelets

  15. Homework Task • Find out about red & white blood cells and platelets (use your textbooks, other books in the library, CD ROMS or internet). • In your own words, describe the function of each of the 3 blood cells.

  16. Blood cells • Red blood cells (erythrocytes) are extremely small and give the blood its red colour. A typical adult has about 4.8 to 5.4 million red blood cells. • The main function of these cells is to transport oxygen and carbon dioxide around the body. Oxygen is transported via a chemical called haemoglobin.   • White blood cells (leukocytes) have the function of protecting the body from bacteria, viruses, infections and foreign bodies • Platelets (thrombocytes) are small cell fragments which help the blood to clot.

  17. Heart Rate • Heart rate…the number of times per minute that the heart contracts. • RHR averages 60 to 80 beats per minute (bpm); can range from 28 bpm to above 100 bpm. • Tends to decrease with age and with increased cardiovascular fitness. • Therefore resting heart rate is often used to indicate a person’s fitness level. • Is affected by environmental conditions such as altitude and temperature What other factors can affect resting heart rate?

  18. Stroke volume • Stroke Volume…the amount of blood pumped by the heart per contraction (beat). • SV increases with increasing rates of work. • Influences aerobic endurance capacity when working maximally. Stroke Volume Increases During Exercise • Frank Starling mechanism—more blood in the ventricle causes it to stretch more and contract with more force.

  19. Cardiac output • Cardiac Output… the amount of blood pumped by the heart per minute. • Resting value of cardiac output (Q) is approximately 5.0 L/min. • Q increases directly with increasing exercise intensity to between 20 to 40 L/min. • Value of increase varies with body size and fitness level. How can you calculate the Cardiac Output? • Q = HR x SV • When exercise intensity exceeds 40% to 60% of maximum, further increases in Q are more a result of increases in HR than SV.

  20. CHANGES IN HR, SV, AND Q

  21. The Heart in Action Complete the table [remember there are 1000ml in a litre!]

  22. Measuring pulse rate

  23. The Heart in Action • The data on the next slide show a person’s heart rate before and after a short period of intense exercise. • Using graph paper or a spreadsheet package (e.g. Excel), plot a line graph. • Use Time on the horizontal axis and Heart Rate on the vertical axis. • Draw a smooth curve through the points and give your graph a title. • Describe what happens to the person’s heart rate during the 15 minutes it was measured.

  24. Resting: 68 bpm Brisk uphill walking: 142 bpm Running uphill: 188 bpm Compare the data on the left by… Drawing a bar chart. Writing a few sentences to explain why the values have changed. Working out the percentage of the person’s maximum heart rate at each intensity. This is estimated as 220 – age (the data is from a 17 year old person). Heart Rate During Different Activities

  25. Circulatory system & PEP • What type of activities/training programmes might be affected by the efficiency of the circulatory system? • Baseline data: measure RHR, HR max & HR rec., plus BP – are there changes during and after the training programme? • If so, what are the changes caused by?

  26. Homework 1. What are the components of the circulatory system? (3 marks) 2. What type of muscle makes up the heart, why is it special? (2 marks) 3. There are three types of blood vessels. Describe each type. (5 marks) 4. Label the diagram below, which demonstrates passage of blood through the heart and around the body. (10 marks)

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