The Circulatory and Respiratory Systems

Transcription

1 BC Science 8 CH02 11/5/06 11:39 AM Page 32 The Circulatory and Respiratory Systems Textbook pages Before You Read Section 2.3 Summary How do you think oxygen from the air you breathe gets into your blood? Record your ideas below. Mark the Text Check for Understanding As you read this section, stop and reread any parts you do not understand. Highlight all the sentences that help you get a better understanding. Reading Check 1. Which blood vessels carry blood to the body from the heart? What structures and organs make up the circulatory system? The circulatory system is the system that moves blood throughout the body. This system includes the heart, blood, and blood vessels. The cells of your body need oxygen to work and stay healthy. Blood is a liquid mixture that includes red blood cells. Red blood cells carry the oxygen that body cells need. When body cells use oxygen, they make carbon dioxide gas as a waste. Red blood cells also carry this waste gas away so it can leave the body. To reach all the cells of your body, blood moves through a network of tubes. These tubes are called blood vessels. There are three types of blood vessels. Arteries are thick-walled blood vessels that move blood rich with oxygen to all the cells of the body. Veins are thinner-walled blood vessels that bring blood back to the heart and lungs so it can be enriched with oxygen again. Capillaries are very thin blood vessels that link arteries with veins. Oxygen diffuses from capillaries into cells. Carbon dioxide diffuses from cells into capillaries. How does the heart work? The role of the heart is to pump blood through the blood vessels. The heart has four chambers. The two upper chambers are the right atrium and the left atrium. The two lower chambers are the right ventricle and the left ventricle. Blood moves through the heart in the order described on the next page. 32 MHR The Circulatory and Respiratory Systems 2006 McGraw-Hill Ryerson Limited

2 BC Science 8 CH02 11/5/06 11:39 AM Page 33 Section 2.3 Summary Find each of these locations in the diagram below. Blood that is low in oxygen flows from veins into the right atrium. The right atrium sends this blood to the right ventricle. The right ventricle sends the blood to the lungs so that it can be enriched with oxygen. The oxygen-rich blood moves back from the lungs to the heart and enters the left atrium. The left atrium sends this blood to the left ventricle. The left ventricle sends oxygen-rich blood to the whole body through the arteries. What structures and organs make up the respiratory system? The respiratory system is made up of two lungs and a series of passages that bring oxygen into the body and move carbon dioxide out of it. The passages lead from the nose, down the throat, and into two air tubes called bronchi. These tubes branch into a series of smaller air tubes called bronchioles. The bronchioles end at thin-walled sacs called alveoli. The alveoli are surrounded by many capillaries. During gas exchange, oxygen and carbon dioxide change places between the alveoli and the capillaries. Oxygen from the air you inhale moves from the alveoli into the blood in the capillaries. Now the blood is enriched with oxygen. It can go back to the heart to be pumped to the cells in the body. While the blood is enriched with oxygen, carbon dioxide waste moves from the blood in the capillaries to the alveoli. Now this waste gas can leave the body when you exhale. capillaries blood sent to whole body through arteries left atrium continued Reading Check 2. Where does gas exchange take place? right atrium right lung right ventricle left ventricle left lung 2006 McGraw-Hill Ryerson Limited The Circulatory and Respiratory Systems MHR 33

3 BC Science 8 CH02 11/5/06 11:39 AM Page 34 Applying Knowledge Use with textbook page 84. Follow the blood through the heart Read the description below of how the blood travels through the heart. Number and label each step in the diagram. The first step is numbered for you. Then use a coloured pencil or pen to trace the flow of blood in the diagram from number one all the way through to number six. 1. right atrium 1. Blood that is low in oxygen flows from veins into the right atrium. 2. The right atrium sends this blood to the right ventricle. 3. The right ventricle sends the blood to the two lungs so that it can be enriched with oxygen. 4. The oxygen-rich blood moves back from the lungs to the heart and enters the left atrium. 5. The left atrium sends this blood to the left ventricle. 6. The left ventricle sends oxygen-rich blood to the whole body through the arteries. 34 MHR The Circulatory and Respiratory Systems 2006 McGraw-Hill Ryerson Limited

4 BC Science 8 CH02 11/5/06 11:39 AM Page 35 Vocabulary Use textbook pages Respiration match-up Match each Term on the left with the best Descriptor on the right. Each Descriptor may be used only once. You will not need to use all the Descriptors. Term 1. respiratory system 2. alveoli 3. capillaries 4. bronchi 5. exhale 6. oxygen 7. bronchioles 8. carbon dioxide 9. inhale 10. change places Descriptor A. two air tubes B. moves from the alveoli into the capillaries C. made of two lungs and a series of passages D. moves from the capillaries into the alveoli E. these surround the alveoli F. oxygen and carbon dioxide do this in the respiratory system G. chamber in the heart H. oxygen enters your body when you do this I. carbon dioxide leaves your body when you do this J. small tubes branching from bronchi K. thin-walled sacs 2006 McGraw-Hill Ryerson Limited The Circulatory and Respiratory Systems MHR 35

5 BC Science 8 CH02 11/5/06 11:39 AM Page 36 Interpreting Illustrations Use with textbook pages Blood vessels Blood is carried from your heart through your body in three types of blood vessels. each type of blood vessel and describe its job. A. B. C. : Describe its job: : Describe its job: : Describe its job: 36 MHR The Circulatory and Respiratory Systems 2006 McGraw-Hill Ryerson Limited

6 BC Science 8 CH02 11/5/06 11:39 AM Page 37 Assessment Use with textbook pages The circulatory and respiratory systems Circle the letter of the best answer. 1. Blood is transported to the heart through A. veins B. arteries C. capillaries D. bronchioles 2. Red blood cells A. carry the oxygen that body cells need B. carry away waste gas C. both A and B D. neither A nor B 3. The two upper chambers in the heart are A. the right ventricle and the left ventricle B. the right atrium and the left atrium C. the right ventricle and the right atrium D. the left ventricle and the left atrium 4. The heart is a(n) A. cell B. tissue C. organ D. organ system 5. Oxygen enters your body when you A. inhale B. exhale C. both A and B D. none of the above 6. Carbon dioxide leaves your body when you A. inhale B. exhale C. both A and B D. none of the above 7. The left ventricle sends oxygen-rich blood A. from the lungs to the heart B. to the two lungs C. from the veins into the right atrium D. to the whole body through the arteries Term Match each Term on the left with the best Descriptor on the right. Each Descriptor may be used only once. 8. respiratory system 9. circulatory system 10. veins 11. arteries 12. blood 13. gas exchange 14. alveoli 15. capillaries Descriptor A. two air tubes B. bring blood back to the heart and lungs C. thin-walled sacs D. this system moves blood throughout the body E. move blood to all the cells in the body F. oxygen and carbon dioxide change places G. mixture that includes red blood cells H. this system brings oxygen into the body and moves carbon dioxide out of it I. link arteries with veins 2006 McGraw-Hill Ryerson Limited The Circulatory and Respiratory Systems MHR 37