2023 Teacher_Transport in Human_Notes.pdf

3G3 Science (Biology) Chapter 6 Notes JURONG WEST SECONDARY SCHOOL SECONDARY THREE – SCIENCE BIOLOGY Chapter 6: TRANSPORT IN HUMANS Learning Ou...

3G3 Science (Biology) Chapter 6 Notes JURONG WEST SECONDARY SCHOOL SECONDARY THREE – SCIENCE BIOLOGY Chapter 6: TRANSPORT IN HUMANS Learning Outcomes: Candidates should be able to: (a) name the main blood vessels to and from the heart, lungs, liver and kidney (b) state the functions of blood red blood cells – haemoglobin and oxygen transport white blood cells – phagocytosis, antibody formation and tissue rejection platelets – fibrinogen to fibrin, causing clotting plasma – transport of blood cells, ions, soluble food substances, hormones, carbon dioxide, urea, vitamins, plasma proteins (c) relate the structure of arteries, veins and capillaries to their functions (d) describe the structure and function of the heart in terms of muscular contraction and the working of valves (histology of the heart muscle, names of nerves and transmitter substances are not required) (e) describe coronary heart disease in terms of the occlusion of coronary arteries and list the possible causes, such as diet, stress, smoking, and the possible preventative measures ACTIVITY: You will be learning from the expert how to dissect a heart. (The video may make some of you uncomfortable.) As the expert explains how to dissect the heart, he will introduce the different parts of the heart. Fill the parts of the heart (No. 1 – 9) in Fig. 1.1 as the expert speaks. 1. right atrium 2. right ventricle 3. left atrium 4. left ventricle 5. pulmonary arteries 6. aorta 7. superior vena cava 8. inferior vena cava 9. pulmonary vein 1  3G3 Science (Biology) Chapter 6 Notes Fig. 1.1 Why the need for circulatory system? Unicellular organisms do not need a transport system for exchange or distribution of materials. No part of the cell is far from environment outside. Exchange of materials occurs easily by diffusion. 2  3G3 Science (Biology) Chapter 6 Notes What about multicellular organisms like us?’ Commented [PLX1]: In multicellular organisms, numerous cells are situated deeps in the body, far from external environment. Simple diffusion alone CANNOT bring enough oxygen and food In multicellular organisms, numerous cells are situated deep in the materials into the cells, and CANNOT remove waste products. So we need a transport system. body, far from external environment. Simple diffusion alone CANNOT bring enough oxygen and food materials into the cells, and CANNOT remove waste products. So we need a transport system to transport these efficiently. Functions of the circulatory system 1. Transporting substances around the body. These include oxygen, glucose, carbon dioxide, nutrients, water and waste products. 2. Controlling body temperature. 3. Protecting the body. Blood contains cells and anti-bodies that fight infection and clotting agents to stop bleeding. The double circulatory system The pulmonary circulation carries: deoxygenated blood from the heart to the lungs oxygenated blood back from the lungs to the heart, ready to be pumped out to the body. The systemic circulation carries: oxygenated blood to the rest of the body through the arteries deoxygenated blood back to the heart through the veins. 3  3G3 Science (Biology) Chapter 6 Notes The circulatory system Deoxygenated blood is Oxygenated blood pumped from the heart from the lungs returns to the lungs through the to the heart through pulmonary artery. the pulmonary vein. Deoxygenated blood returns to the heart Oxygenated blood is from all parts of the pumped at high pressure body through the vena from the ventricle to the cava. body through the aorta. Components of the Circulatory System 1. The Human Heart 2. The Blood Vessels 1. The Human Heart Located in the thoracic cavity, between the two lungs and slightly to the left. About the size of a clenched fist. Weighs around a ½ pound The four chambers of the heart have special names: o An upper chamber is called an atrium (plural: atria). o A lower chamber is called a ventricle. Fig. 1.1 4  3G3 Science (Biology) Chapter 6 Notes Here are some other important parts of the heart: Fig. 1.2 Pathway of blood through the heart Fig. 1.3 5  3G3 Science (Biology) Chapter 6 Notes Questions: 1. Does the whole heart pump together? Or does it have a order to which part of the heart contracts first? No, the atria muscles will contract first, followed by the ventricle muscles. ………………………………………………………………… ………………………………………………………………… ………………………………………………………………… 2. What do we call the blood vessels that are supplying oxygen to the heart muscles? Coronary artery ……………………………………………. 3. The figure on the right shows an external view of the heart. State the name and function of the tissue that makes up the part labelled L. Name: Cardiac muscle tissue of the left ventricle Function: cardiac muscles can contract, which creates a force to move the blood in the left ventricle of the heart out of the aorta. ……………………………………………………………….. ……………………………………………………………….. ……………………………………………………………….. Commented [PLX2]: Name: Cardiac muscle tissue of the left ventricle Function: it can contract, which creates a force to move the blood in the ventricle of the heart out of the aorta. CLASS DISCUSSION: The HEART (Exterior view) Are you able to recognise the blood vessels? Where do you think are the atrium & the ventricle? 6  3G3 Science (Biology) Chapter 6 Notes EXTENSION: How do you think the heart of the fish is different from ours? What do you think is the reason for the Commented [PLX3]: Fish have a single circulatory system difference? meaning that blood only passes through the heart once on one complete circuit around the blood system of the body. 7  3G3 Science (Biology) Chapter 6 Notes Blood Pressure changes in The Heart Blood pressure is the FORCE that blood exerts on the walls of blood vessels. Refer to Fig. 1.4. What can you deduce about this graph? What can you conclude? Fig. 1.4 BSSB: A: Bicuspid, B: Semi-lunar, C: Semi-lunar, D: Bicuspid COCO: A: Closed, B: Open, C: Closed, D: Open 8  3G3 Science (Biology) Chapter 6 Notes 2. The Blood Vessels There are three types of blood vessels, as shown in Fig. 2.1 and 2.2. Fig. 2.1 Fig. 2.2 9  3G3 Science (Biology) Chapter 6 Notes 2.1 The Blood Vessels – Arteries Transport oxygenated blood away from the heart to other organs in the body. Except (pulmonary artery) Have thick, muscular walls to withstand high blood pressure (10 – 16kPa*) from blood coming from the heart and to prevent it from bursting. Blood flows in pulses. Blood flows rapidly. *SI unit for pressure: Kilopascal 2.2 The Blood Vessels - Veins Transport deoxygenated blood back to the heart. Except (pulmonary vein) Have relatively thin walls with little elastic tissue as flow of blood is at low pressure. (1 kPa) Have semi-lunar valves present throughout (except the largest veins) 10  3G3 Science (Biology) Chapter 6 Notes Blood does not flow in pulses. Blood flow is slow. 11  3G3 Science (Biology) Chapter 6 Notes 2.3 The Blood Vessels - Capillaries No muscles No elastic tissues Links arteries to veins Blood changes from oxygenated to deoxygenated Blood pressure reducing. (4-1 kPa) – WHY? (lumen is small) Blood flows slowly. Numerous and highly branched → provides a larger surface area for diffusion One cell thick endothelium wall →allows rapid diffusion of materials between blood and cells due to the short distance 12  3G3 Science (Biology) Chapter 6 Notes Blood Pressure changes in The Blood Vessels Blood pressure is the FORCE that blood exerts on the walls of blood vessels. Blood pressure varies in different parts of the body. CLASS DISCUSSION: Where is the highest pressure in the body? Why do you think so? Write your thoughts here. Commented [PLX4]: Aorta Aorta – it’s where the heart muscles are contracting the hardest to create a pressure high enough to force the blood out of the ventricle and towards the rest of the body EXTENSION: “High blood pressure may occur temporarily after 2.4km run.” “My heart rate is 188 beats per minute during 2.4km run.” Do you think these statements are true? Talk about it with your partner. Commented [PLX5]: 2.4 km run; Need more energy Faster rate of respiration to release energy required Need more glucose and oxygen Heart need to pump faster (increased heart rate) and harder (high pressure) to deliver glucose and oxygen to the muscle cells. 13  3G3 Science (Biology) Chapter 6 Notes 2.4 The MAIN Blood Vessels To and from the liver; To and from the kidney; 14  3G3 Science (Biology) Chapter 6 Notes 2.4 The Main Blood Vessels - Overview The BLOOD It is made up of plasma, red blood cells, white blood cells and platelets. Function: 1. Blood is the body’s means of transporting substances around. It transports: oxygen from the lungs to the heart and then to the body’s tissues by red blood cells. materials like hormones (e.g. insulin) from one organ to another by plasma. nutrients (e.g. glucose) and minerals (e.g. sodium) from the intestines to the tissues by plasma. metabolic waste products such as urea and carbon dioxide) to the kidneys. 15  3G3 Science (Biology) Chapter 6 Notes 2. Blood is the body’s means of protecting the body. It protects the body by: defence mechanism of white blood cells. Phagocytosis & production of antibodies Commented [PLX6]: phagocyte Commented [PLX7]: lymphocyte The BLOOD – PLASMA The blood cells and platelets are suspended in a substance called plasma. Plasma is made up of: 90% water inorganic salts glucose antibodies urea and other waste products plasma proteins. 16  3G3 Science (Biology) Chapter 6 Notes The BLOOD - RED BLOOD CELLS Also called erythrocytes. Made in the bone marrow. Transport oxygen to the tissues. Red blood cells (RBC) a) Contains a) Haemoglobin combines reversibly with pigment oxygen to form oxyhaemoglobin to haemoglobin. enable RBC to transport oxygen from the b) It is circular, lungs to all cells in the body. flattened b) This increase surface area to volume ratio biconcave disc. to absorb and release oxygen at a faster c) To does not rate. possess a c) It is to carry more haemoglobin and thus nucleus. more oxygen. d) It is elastic and d) This ensures it is able to squeeze through can turn into a blood vessels smaller than itself in bell shape. diameter. (weak point. Avoid using) (weak point. Avoid using) EXTENSION: Role of blood in achieving sports potential HOW CAN LIVING AT ALTITUDE IMPROVE ATHLETES PERFORMANCE? Red blood cells carry oxygen, which is vital to muscle action, it is advantageous for a performer to have a high red blood cell count, especially in endurance events. When athletes train and live at altitude, where there is less oxygen in the air, their bodies compensate by producing extra red blood cells. This means that they can perform at a higher intensity than other athletes when performing at sea level. 17  3G3 Science (Biology) Chapter 6 Notes The BLOOD - WHITE BLOOD CELLS Also called leucocytes. They are bigger than red blood cells and have large nuclei. Act as the body’s defence systems. Some white blood cells surround and engulf harmful microbes. They will then be digested. – PHAGOCYTES o Process: Phagocytosis Some produce chemicals called antibodies that fight specific pathogen - LYMPHOCYTES o Antibodies destroy the bacteria ▪ by causing their surface membrane to rupture; ▪ causing them to clump together or agglutinate so that they can be easily ingested by phagocytes; o Antibodies neutralise harmful toxins produced by bacteria. e.g. 18  3G3 Science (Biology) Chapter 6 Notes The BLOOD - PLATELETS Also known as thrombocytes They are not true cells. They are a membrane bound fragments of cytoplasm from bone marrow cells. They play a part in blood clotting. Blood clotting process; Thrombokinase + calcium ions 19  3G3 Science (Biology) Chapter 6 Notes CORONARY HEART DISEASE The most common heart disease. It is a disease affecting the coronary arteries which supply blood to the heart muscle. Blood supply to the heart muscles can be greatly reduced and this can lead to a HEART ATTACK. o Greatly reduced blood flow to a certain part of the heart muscle. o Heart muscles do not receive sufficient oxygen and nutrient such as glucose. o The region of the heart muscle dies. https://www.webmd.com/heart-disease/guide/cardiac-catheterization1#1 Causes of Coronary Heart Disease o A high-fat diet rich in cholesterol and saturated animal fats o Emotional stress o Smoking o Sedentary lifestyle 20  3G3 Science (Biology) Chapter 6 Notes In a normal artery, blood is able to flow through smoothly. Fatty substances such as cholesterol and saturated fats may be deposited on the inner walls of the coronary arteries. Lumen of these arteries are narrowed. A rough inner surface is developed. Fibrinogen in the plasma deposits fibrin on it, causing a thrombus (blood clot) to form. 21  3G3 Science (Biology) Chapter 6 Notes Extension: Figure below shows a Stent Heart Surgery that will be done in patients. Do you think this is effective in preventing future occurrence of coronary heart disease? Discuss with your partner. https://www.michaelwest.com.au/inside-the-stent-investigating-the-boom-in-cardiac-surgery/ Discussion: Preventive measures against Coronary Heart Disease The End 22