2. The Circulatory System of Humans

3. What is that ‘lub dub, lub, dub’ noise in my chest? The noise is the sound of your heart as it pumps blood.

4. The heart Your heart pumps blood all the time to all parts of your body. Your heart is made of heart muscle. The heart muscle contracts and relaxes continuously. You cannot control your heart muscle. You are reminded that under the Copyright Act, it is an offence to reproduce or copy any part of this presentation without permission from Times Media Private Limited.

5. The heart

6. Blood vessels Blood vessels are tubes which carry blood to different parts of your body. There are 3 types of blood vessels: –artery –vein –capillary

7. Blood vessels Artery Vein Capillaries ª Veins carry blood –rich in carbon dioxide –back to the heart ª Arteries carry blood –rich in oxygen –from your heart to all parts of your body

8. Blood vessels ª Capillaries –have very thin walls –allow oxygen, digested food, water, carbon dioxide and waste materials to pass through their walls Artery Vein Capillaries

9. Circulatory system Your heart, blood vessels and blood form the parts of the circulatory system. The circulatory system circulates blood from your heart to all parts of your body and back again.

10. lungs heart upper body parts lower body parts flow of blood rich in oxygen, digested food and water flow of blood rich in carbon dioxide and waste materials Blood circulation

11. The heart is an organ that is made of a special muscle called the heart muscle. The heart muscle contracts and relaxes repeatedly without rest! What is the Heart and what it does

12. What causes blood flow? By contracting, the heart muscle squeezes blood out of the heart into thick-walled blood vessels. This causes blood to flow to all parts of our body. By relaxing, heart muscle makes blood flow back into heart from thin-walled blood vessels. thick-walled blood vessels thin-walled blood vessels

13. Blood Circulation: Step 1 Your heart pumps oxygen-rich blood to all cells of your body. Your body cells use the oxygen, digested food and water from the blood to produce energy.

14. Blood Circulation: Step 1 from lungs ª Your heart pumps oxygen-rich blood to all cells of your body. ª Your body cells use the oxygen, digested food and water from the blood to produce energy.

15. Blood Circulation: Step 1 ª Your heart pumps oxygen-rich blood to all cells of your body. ª Your body cells use the oxygen, digested food and water from the blood to produce energy.

16. Blood Circulation: Step 1 to the body ª Your heart pumps oxygen-rich blood to all cells of your body. ª Your body cells use the oxygen, digested food and water from the blood to produce energy.

17. Blood Circulation: Step 2 ª As blood goes around your body, it picks up carbon dioxide and waste materials. I’ve passed the waste to the kidneys and liver. ª On its way back to your heart, blood passes the waste materials to the excretory organs like your kidneys and liver.

18. Blood Circulation: Step 2 ª As blood goes around your body, it picks up carbon dioxide and waste materials. ª On its way back to your heart, blood passes the waste materials to the excretory organs like your kidneys and liver. ª When blood reaches your heart again, it is sent to the lungs where carbon dioxide is removed. Next, to remove the carbon dioxide.

19. Blood Circulation: Step 2 ª As blood goes around your body, it picks up carbon dioxide and waste materials. ª On its way back to your heart, blood passes the waste materials to the excretory organs like your kidneys and liver. ª When blood reaches your heart again, it is sent to the lungs where carbon dioxide is removed.

20. Blood Circulation: Step 2 ª As blood goes around your body, it picks up carbon dioxide and waste materials. ª On its way back to your heart, blood passes the waste materials to the excretory organs like your kidneys and liver. ª When blood reaches your heart again, it is sent to the lungs where carbon dioxide is removed.

21. Blood Circulation: Step 2 ª As blood goes around your body, it picks up carbon dioxide and waste materials. ª On its way back to your heart, blood passes the waste materials to the excretory organs like your kidneys and liver. ª When blood reaches your heart again, it is sent to the lungs where carbon dioxide is removed.

22. Blood Circulation: Step 2 ª As blood goes around your body, it picks up carbon dioxide and waste materials. ª On its way back to your heart, blood passes the waste materials to the excretory organs like your kidneys and liver. ª When blood reaches your heart again, it is sent to the lungs where carbon dioxide is removed. To the lungs

23. Heartbeat Each heartbeat is a cycle of contraction and relaxation of our heart muscle. Each heartbeat is a cycle of contraction and relaxation of our heart muscle. As heart muscle contracts and relaxes, it produces repeated sounds - "lub dub", "lub dub", "lub dub"... As heart muscle contracts and relaxes, it produces repeated sounds - "lub dub", "lub dub", "lub dub"...

24. Blood is squeezed out of the ventricles (that is, the lower chambers of the heart) “Lub” sound Blood flows into the ventricles “dub” sound

25. Contraction and relaxation of heart muscle causes pressure along our blood vessels to rise and fall - this is known as Pulse. Contraction and relaxation of heart muscle causes pressure along our blood vessels to rise and fall - this is known as Pulse. After every heartbeat, a pressure wave passes along your blood vessels. After every heartbeat, a pressure wave passes along your blood vessels. By pressing your fingers against your wrist, you can feel your pulse. By pressing your fingers against your wrist, you can feel your pulse. Press your fingers gently against your wrist. Pulse, Pulse rate and how to measure it The number of times pulse occurs in one minute is known as Pulse Rate. The number of times pulse occurs in one minute is known as Pulse Rate. You can obtain pulse rate by counting the number of times pulse occurs in one minute. You can obtain pulse rate by counting the number of times pulse occurs in one minute.

26. The rate of your heartbeat changes with: BABY About 120 times per minute ADULT About 70 - 90 times per minute ª age ª health

27. Slow Fast The rate of your heartbeat changes with the type of activity you are doing ª When you exercise, your heart rate increases. The heart needs to supply more food and oxygen to various parts of the body to produce more energy.