KS3 Biology Circulation and Respiration PDF

KS3 Biology Circulation and Respiration 1 1 of of 20 26 © Boardworks Ltd 2005 2004 Contents Respiration The circulation system Releasing energy The breathing system Anaerobic respiration Summary activities 1 2 of 20 26 © Boardworks Ltd 2005 2004 The body’s transport system The dissolved food and oxy...

KS3 Biology Circulation and Respiration 1 1 of of 20 26 © Boardworks Ltd 2005 2004 Contents Respiration The circulation system Releasing energy The breathing system Anaerobic respiration Summary activities 1 2 of 20 26 © Boardworks Ltd 2005 2004 The body’s transport system The dissolved food and oxygen needed for respiration are carried around the body by the circulation system. lungs The circulation system includes the blood, blood vessels, the heart and the lungs. Which part of the circulation system actually carries dissolved food and oxygen to the body’s cells? 1 3 of 20 26 body’s cells © Boardworks Ltd 2005 2004 Humans have a closed circulatory system, typical of all vertebrates, in which blood is confined to vessels and is distinct from the interstitial fluid. The heart pumps blood into large vessels that branch into smaller ones leading into the organs. Materials are exchanged by diffusion between the blood and the interstitial fluid bathing the cells. 1 4 of 20 26 © Boardworks Ltd 2005 2004 Three Major Elements (Heart, Blood Vessels, & Blood) 1. The Heart -highly interconnected cells Four chambers Right atrium Right ventricle Left atrium Left ventricle 1 5 of 20 26 © Boardworks Ltd 2005 2004 1 6 of 20 26 © Boardworks Ltd 2005 2004 1 7 of 20 26 © Boardworks Ltd 2005 2004 Circuits Pulmonary circuit –The blood pathway between the right side of the heart, to the lungs, and back to the left side of the heart. Systemic circuit –The pathway between the left and right sides of the heart. 1 8 of 20 26 © Boardworks Ltd 2005 2004 2. Blood Vessels -A network of tubes –Arteries 🡪 arterioles move away from the heart –Capillaries where gas exchange takes place. –Veins 🡪 Venules moves towards the heart 1 9 of 20 26 © Boardworks Ltd 2005 2004 1 10ofof20 26 © Boardworks Ltd 2005 2004 Blood The blood carries oxygen and dissolved food to all the body’s cells so that respiration can take place. 1 11ofof20 26 © Boardworks Ltd 2005 2004 3. The Blood A. Plasma Liquid portion of the blood. Contains clotting factors, hormones, antibodies, dissolved gases, nutrients and waste 1 12ofof20 26 © Boardworks Ltd 2005 2004 B. Erythrocytes – carry hemoglobin and oxygen and do not have a nucleus and live only about 120 days – can not repair themselves 1 13ofof20 26 © Boardworks Ltd 2005 2004 C. Leukocytes – fight infection 1 14ofof20 26 © Boardworks Ltd 2005 2004 D. Thrombocytes – these are cell fragment that are formed in the bone marrow from magakaryocytes – clot Blood by sticking together – via protein fibers called fibrin 1 15ofof20 26 © Boardworks Ltd 2005 2004 Functions of the Heart Generating blood pressure Routing blood – Heart separates pulmonary and systemic circulations Ensuring one-way blood flow – Heart valves ensure one-way flow Regulating blood supply – Changes in contraction rate and force match blood delivery to changing metabolic needs 1 16ofof20 26 © Boardworks Ltd 2005 2004 Your beating heart The heart is made of very special muscle called cardiac muscle. This is because it has to keep beating for the whole of a person’s life! If you tried to do the same action repeatedly (like the heart does), your muscles would get tired and after a while stop working. For example, if you keep clenching and unclenching your hand, it will get tired and may even start to get cramp. Why is it important for respiration that the heart keeps beating? 1 17ofof20 26 © Boardworks Ltd 2005 2004 Disorders of the Circulatory System Anemia - lack of iron in the blood, low RBC count Leukemia - white blood cells proliferate wildly, causing anemia Hemophilia - bleeder’s disease, due to lack of fibrinogen in thrombocytes Heart Murmur - abnormal heart beat, caused by valve problems Heart attack - blood vessels around the heart become blocked with plaque, also called myocardial infarction 1 18ofof20 26 © Boardworks Ltd 2005 2004 Contents Respiration The circulation system Releasing energy The breathing system Anaerobic respiration Summary activities 1 19ofof20 26 © Boardworks Ltd 2005 2004 How is digested food used by the body? The body needs a constant supply of comes from digested food. energy which Glucose from digested carbohydrate is an important substance that contains stored chemical energy. When glucose reacts with oxygen a lot of released. energy is In the body’s cells, glucose and oxygen react to release energy. Some of this is released as heat and the rest is used by the cells. The release of energy from glucose is called… respiration 1 20ofof20 26 © Boardworks Ltd 2005 2004 What is respiration? Respiration is the process that the body uses to release energy from digested food (glucose): gluco se oxyge n carbo n dioxid e from the digestive system from the breathing system waste product exhaled water waste product exhaled ener gy useful! This type of respiration is called aerobic respiration because energy is released with oxygen. How do the glucose and oxygen needed for aerobic respiration get to the all the body’s cells? 1 21ofof20 26 © Boardworks Ltd 2005 2004 Aerobic respiration: word equation activity 1 22ofof20 26 © Boardworks Ltd 2005 2004 Comparing respiration and combustion Burning is the reaction between a fuel and oxygen. This reaction is called combustion: fuel oxyge n carbo n dioxid e water When something burns, heat and light energy are released and carbon dioxide and water are also produced, so combustion is similar to respiration. However, combustion is different because it is not a controlled reaction. Respiration is a controlled reaction which slowly releases energy from food in the body’s cells and the cells do not catch fire! 1 23ofof20 26 © Boardworks Ltd 2005 2004 Different types of activity What happens to the pulse rate whilst someone is running? The body needs to release more energy: so oxygen and glucose need to reach muscle cells quickly; so blood is pumped around the body faster; so the pulse is faster. What happens to the pulse rate whilst someone is sleeping? The body needs to release less energy: so oxygen and glucose need to reach muscle cells slowly; so blood is pumped around the body slower; so the pulse is slower. 1 24ofof20 26 © Boardworks Ltd 2005 2004 Contents Respiration Releasing energy The circulation system The breathing system Anaerobic respiration Summary activities 1 25ofof20 26 © Boardworks Ltd 2005 2004 What is breathing? The breathing system is used by the body to get the oxygen needed for respiration. It is also use to get rid of the waste product of respiration, the gas carbon dioxide. Breathing in and breathing out are separate processes in the body: Breathing in is also known as inhalation. When you inhale you breathe in air, including oxygen, into your lungs. Breathing out is also known as exhalation. When you exhale you breathe out the contents of our lungs and getting rid of the waste gas carbon dioxide. 1 26ofof20 26 © Boardworks Ltd 2005 2004 Inhalation 1 27ofof20 26 © Boardworks Ltd 2005 2004 The alveoli In the lungs, oxygen travels to thousands of tiny air sacs called alveoli. These are covered with tiny blood vessels. The alveoli give the lungs a huge surface area which is equal in size to the area of a tennis court! 1 28ofof20 26 © Boardworks Ltd 2005 2004 Gas exchange Gas exchange takes place in the alveoli – oxygen is transferred into the blood and carbon dioxide moves out of the blood. Each alveolus has a thin wall so that gas exchange between the lungs and the blood can take place quickly. 1 29ofof20 26 © Boardworks Ltd 2005 2004 Exhalation 1 30ofof20 26 © Boardworks Ltd 2005 2004 Comparing inhaled and exhaled air What are the differences between inhaled and exhaled air? inhaled air nitrogen (78%) oxygen (21%) carbon dioxide (0.04%) other exhaled air nitrogen (78%) oxygen (17%) carbon dioxide (4%) other How could you test for the differences between inhaled and exhaled air? 1 31ofof20 26 © Boardworks Ltd 2005 2004 Contents 8B Respiration Releasing energy The circulation system The breathing system Anaerobic respiration Summary activities 1 32ofof20 26 © Boardworks Ltd 2005 2004 Aerobic and anaerobic respiration Aerobic respiration When the body is able to supply the cells with the oxygen and glucose that they need, it carries out aerobic respiration. gluco se oxyge n carbo n dioxid e water ener gy Anaerobic respiration When the body cannot supply the cells with the oxygen needed to break down glucose, then it has to carry out anaerobic respiration. Energy is released without oxygen: gluco se 1 33ofof20 26 lactic acid ener gy © Boardworks Ltd 2005 2004 Not enough oxygen! gluco se lactic acid ener gy When anaerobic respiration takes place, the lactic acid produced soaks the muscle cells and prevents muscles from doing their job. This causes fatigue and sometimes cramp. After activity that has lead to anaerobic respiration, the person involved pants and breathes heavily. This happens because they need lots of oxygen to get rid of lactic acid that has built up in their body. lactic acid 1 34ofof20 26 oxyge n carbo n dioxid e water © Boardworks Ltd 2005 2004 Anaerobic respiration: word equation activity 1 35ofof20 26 © Boardworks Ltd 2005 2004 Contents 8B Respiration Releasing energy The circulation system The breathing system Anaerobic respiration Summary activities 1 36ofof20 26 © Boardworks Ltd 2005 2004 Glossary aerobic – The type of respiration that occurs with oxygen. alveoli – Tiny air sacs in the lungs where gas exchange takes place. anaerobic – The type of respiration that occurs without oxygen. exhalation – The process of breathing out. glucose – A type of sugar that the body releases energy from during respiration. inhalation – The process of breathing in. respiration – The process that the body uses to release energy from digested food. 1 37ofof20 26 © Boardworks Ltd 2005 2004 Anagrams 1 38ofof20 26 © Boardworks Ltd 2005 2004 Multiple-choice quiz 1 39ofof20 26 © Boardworks Ltd 2005 2004