Biology Chapter 5 and 6 PDF

Chapter 5 Nutrition in Humans Biology Matters for GCE ‘O’ Level (3Ed) 1 © 2023 Marshall Cavendish Education Pte Ltd TB eBook Biology Connect Page 73 What nutrients can we obtain from insects? Would you What are the benefits of insects as an alternative source of food? rather eat Which insects can be used in food recipes? an insect? 2 © 2023 Marshall Cavendish Education Pte Ltd Food Nutritional Value Textbook Page 73 The food packaging we ﬁnd in supermarkets usually have nutritional labels that tell us the nutrients and the amount of those nutrients present in the food we are buying. Challenge How does our body get the nutrients present in these food? 3 © 2023 Marshall Cavendish Education Pte Ltd 4 © 2023 Marshall Cavendish Education Pte Ltd 5 © 2023 Marshall Cavendish Education Pte Ltd Chapter 5 Nutrition in Humans 5.1 What Is Nutrition? 5.2 What Is Digestion? 5.3 What Is Absorption? 5.4 What Happens to the Absorbed Nutrients? 5.5 What Are the Effects of Alcohol Consumption? 6 © 2023 Marshall Cavendish Education Pte Ltd 5.1 What Is Nutrition? Learning Outcome(s) Describe the functions of the various parts of the digestive system: mouth, salivary glands, oesophagus, stomach, duodenum, pancreas, gall bladder, liver, ileum, colon, rectum, anus, in relation to ingestion, digestion, absorption, assimilation and egestion of food, as appropriate. Describe peristalsis in terms of rhythmic wave-like contractions of the muscles to mix and propel the contents of the alimentary canal. 7 © 2023 Marshall Cavendish Education Pte Ltd What Is Nutrition? Textbook Page 74 Nutrition is the process by which organisms obtain food and energy for growth, repair and maintenance of the body. It consists of the following processes: Feeding or ingestion: Food is taken into the body. Digestion: Large food molecules are broken down into smaller, soluble molecules that can be absorbed into the body cells. Absorption: Nutrients move from the small intestine into the bloodstream. Assimilation: Nutrients are used by cells to provide energy or to make new cytoplasm for growth. Egestion: Undigested matter is removed from the body. 8 © 2023 Marshall Cavendish Education Pte Ltd Group Activity Why does food need to be digested? 9 © 2023 Marshall Cavendish Education Pte Ltd Video Time! Food moving through your body https://www.youtube.com/watch?v=_QYwscALNn g 10 © 2023 Marshall Cavendish Education Pte Ltd The Mouth and the Buccal Cavity Textbook Page 75 Food enters the body through the mouth, which leads into the buccal cavity. 11 © 2023 Marshall Cavendish Education Pte Ltd Consider… Textbook Page 74 Why do people choke when they talk while eating? What prevents food from going down your windpipe? 12 © 2023 Marshall Cavendish Education Pte Ltd Pharynx Textbook Page 76 It connects the buccal cavity to the oesophagus, larynx (voice-box) and trachea (windpipe). The glottis is a slit located at the larynx. Both food and air pass through the pharynx when they enter the body. Air passes through the trachea, while food passes through the oesophagus. The epiglottis closes over the glottis to prevent food from reaching the larynx and trachea when swallowing. People tend to choke when they talk while swallowing, as the epiglottis cannot fully close. 13 © 2023 Marshall Cavendish Education Pte Ltd Video Time! https://www.youtube.com/watch?v=k4FOGogOk4 14 © 2023 Marshall Cavendish Education Pte Ltd E Oesophagus Textbook Page 76 It is a narrow, muscular tube that passes through the thorax (chest) and diaphragm. It connects the mouth and stomach. It consists of a layer of longitudinal muscles and a layer of circular muscles. (inner layer) (outer layer) Note: Circular and longitudinal muscles are present along the whole gut from the oesophagus to the rectum. 15 © 2023 Marshall Cavendish Education Pte Ltd Peristalsis Textbook Page 77 It refers to the rhythmic, wave-like muscular contractions in the wall of the alimentary canal. It enables food to be mixed with digestive juices and helps to push or propel the food along the gut. When the circular muscles contract, they constrict the lumen. When the longitudinal muscles contract, they shorten and widen the lumen. These muscles are antagonistic, so when one set of muscles contracts, the other relaxes. 16 © 2023 Marshall Cavendish Education Pte Ltd Textbook When the circular muscles contract, the longitudinal muscles relax. As Page 77 a result, the gut becomes narrower and longer (constricts). The food is squeezed or pushed forward. When the longitudinal muscles contract, the circler muscles relax. The gut becomes wider and shorter (dilates), allowing food to enter the lumen. 17 © 2023 Marshall Cavendish Education Pte Ltd Stomach Textbook Page 77 Lies beneath the diaphragm, to the left side of the abdomen, and is partly covered by the liver Has numerous pits and gastric glands found in the stomach lining Has gastric glands which secrete gastric juice that play an important part in digestion 18 © 2023 Marshall Cavendish Education Pte Ltd Small Intestine Textbook Page 78 Consists of a U-shaped duodenum and the much-coiled ileum Carries out most of the digestive processes Contains glands, in the wall lining, that secrete digestive enzymes Enzymes in the small intestine speed up the digestion of food Absorbs water and nutrients from food, 19 which usually takes place in the ileum © 2023 Marshall Cavendish Education Pte Ltd Large Intestine Textbook Page 78 Is shorter and broader than the small intestine Consists of the colon, rectum and anus Absorbs remaining water and mineral salts from undigested food Temporarily stores faeces in the rectum 20 © 2023 Marshall Cavendish Education Pte Ltd Liver Textbook Page 78 Largest gland in the body, located below the diaphragm. Three blood vessels are attached to the lower surface of the liver: the hepatic portal vein, the hepatic vein, and the hepatic artery. Liver cells produce and secrete bile, which contain bile salts that aid in the emulsification of fats. 21 © 2023 Marshall Cavendish Education Pte Ltd Gall bladder Textbook Page 78 The gall bladder is attached to the liver. Bile, produced by the liver, is stored temporarily in the gall bladder. When the gall bladder contracts, bile flows via the bile duct into the duodenum, which is part of the small intestine. 22 © 2023 Marshall Cavendish Education Pte Ltd Pancreas Textbook Page 79 It is connected to the duodenum by the pancreatic duct. The bile duct joins the pancreatic duct before the pancreatic duct opens into the duodenum. It produces pancreatic juice, which contains digestive enzymes such as amylase, lipase and protease. Secretes the hormones insulin and glucagon, which help regulate the blood sugar concentration in the body. 23 © 2023 Marshall Cavendish Education Pte Ltd What is acid reflux? How can it be prevented? https://youtu.be/Og5xAdC8EUI 24 © 2023 Marshall Cavendish Education Pte Ltd Recall this definition that you learned in the previous section: Digestion The process whereby large food molecules are broken down into smaller, soluble molecules that can be absorbed into the body cells. Which processes from the previous section before would you categorise as aiding in digestion? Chewing Secretion and mixing of saliva with food Closing of the epiglottis Peristalsis Secretion of gastric juice into the stomach Secretion of bile into the small intestine Absorption of water in the small and large intestines 25 © 2023 Marshall Cavendish Education Pte Ltd Video Time! Before this, note that enzymes are found in gastric/intestinal juice and they aid in digestion. https://www.youtube.com/watch?v=XTUm-75-PL 4 26 © 2023 Marshall Cavendish Education Pte Ltd Till timestamp 2:14 Chapter 5 Nutrition in Humans 5.1 What Is Nutrition? 5.2 What Is Digestion? 5.3 What Is Absorption? 5.4 What Happens to the Absorbed Nutrients? 5.5 What Are the Effects of Alcohol Consumption? 27 © 2023 Marshall Cavendish Education Pte Ltd 5.2 What Is Digestion? Learning Outcome(s) Describe the functions of enzymes (e.g. amylase, maltase, protease, lipase) in digestion, listing the substrates and end-products. 28 © 2023 Marshall Cavendish Education Pte Ltd Textbook Digestion Page 80 Physical Digestion Chemical Digestion Involves the mechanical break-up of Involves the breaking down of large food into small particles. molecules in food, such as proteins, Examples: starch and fats, into small, soluble Food being chewed in the mouth Churning action of the stomach molecules that can be absorbed. Emulsification of fats by bile salts This is done with the help of enzymes. Physical digestion increases the surface area-to-volume ratio of ingested food so that digestive enzymes can act of the food particles more eﬀectively 29 © 2023 Marshall Cavendish Education Pte Ltd Textbook Processes That Take Place in the Mouth Page 80 1. Salivary glands are stimulated to secrete saliva. 2. Saliva mixes with the food and softens it. 3. The salivary amylase in saliva digests starch to maltose. 4. The optimum pH for salivary amylase is at pH 7. 5. The food is broken down into smaller pieces by chewing, which increases the surface area-to-volume ratio for salivary amylase to work on. 6. The food is rolled into small round masses called boli. 7. The boli are swallowed and passed down into the oesophagus via the pharynx. 30 © 2023 Marshall Cavendish Education Pte Ltd Textbook Processes That Take Place in the Stomach Page 81 1. Gastric glands are stimulated to secrete gastric juice. 2. Peristalsis churns and breaks up the food and mixes the food with gastric juice. 3. Gastric juice contains hydrochloric acid, mucus and protease (enzyme that digests proteins). 4. Hydrochloric acid (about pH 2) has the following functions: – stops the action of salivary amylase by denaturing it – provides a low pH environment in the stomach for protease to digest proteins – kills microorganisms in food. 5. Protease digests proteins into polypeptides. 6. The food remains in the stomach for 3–4 hours, becoming partially digested substance called chyme. 7. Chyme passes into the duodenum in small amounts. 31 © 2023 Marshall Cavendish Education Pte Ltd Textbook Processes That Take Place in the Small Intestine Page 82 1. As chyme enters the duodenum, it stimulates the pancreas to secrete pancreatic juice. 2. The pancreatic juice passes to the duodenum via the pancreatic duct. 3. Pancreatic juice contains the enzymes pancreatic amylase, protease and pancreatic lipase. 4. The gall bladder releases bile (produced by the liver and stored in the gall bladder) into the duodenum via the bile duct. As bile does not contain enzymes, it cannot digest food. Bile speeds up the digestion of fats by breaking up large fat molecules into smaller fat molecules. 5. The small intestines produces enzymes maltase, protease and lipase. 6. The acidic chyme from the stomach is neutralised by the alkaline fluids from the pancreas, gall bladder and small intestine, thus achieving a pH of 8, which is suitable for digestion in the small intestine. 32 © 2023 Marshall Cavendish Education Pte Ltd Textbook Past to Present Page 81 Challenge Do you think his way of proving to the scientific community is an example to follow, or was he being too reckless? Explain your position. 33 © 2023 Marshall Cavendish Education Pte Ltd Textbook Digestion of Different Foods Page 82 Carbohydrate Digestion Examples of carbohydrates include starch, sucrose and cellulose. Carbohydrates are digested by carbohydrases such as amylase and maltase. Starch is broken down into maltose by amylase in the mouth and small intestine. Maltose is broken down into glucose by maltase in the small intestine. 34 © 2023 Marshall Cavendish Education Pte Ltd Textbook Protein Digestion Page 82 Proteins are digested by proteases. Protein digestion starts in the stomach, where stomach protease digests proteins to polypeptides. The undigested proteins that enter the small intestine are digested by intestinal protease to polypeptides. The polypeptides produced are further digested to amino acids by intestinal protease. 35 © 2023 Marshall Cavendish Education Pte Ltd Textbook Fat Digestion Page 83 Bile is released into the duodenum, and the bile salts emulsify fats by lowering the surface tension of the fats. Thus, the fats break into tiny fat droplets, increasing the surface area-to-volume ratio for enzyme action. Emulsified fats are digested by lipases into fatty acids and glycerol in the small intestine. 36 © 2023 Marshall Cavendish Education Pte Ltd Summary Substrate Enzyme Product Starch Amylase Maltose Maltose Maltase Glucose Protein Protease Polypeptides Polypeptides Protease Amino acids Fats Lipase Fatty acids and glycerol 37 © 2023 Marshall Cavendish Education Pte Ltd Textbook Biology Connect Page 84 Scan the QR code on TB p. 84 and have students take part in an interactive animation on digestion of food. 38 © 2023 Marshall Cavendish Education Pte Ltd Textbook Organs and Enzymes Involved in Digestion Pages 83–84 39 © 2023 Marshall Cavendish Education Pte Ltd Group Work Work together to draw a concept map on digestion. Share with the class the concept map done by your group. 40 © 2023 Marshall Cavendish Education Pte Ltd Revision Time! Recall what you know about diffusion and active transport. How do you think diffusion and active transport are related to absorption in the small intestine? https://www.youtube.com/watch?v=ufCiGz75D Ak 41 © 2023 Marshall Cavendish Education Pte Ltd Video Time! How does absorption in the small intestine occur? 42 © 2023 Marshall Cavendish Education Pte Ltd Chapter 5 Nutrition in Humans 5.1 What Is Nutrition? 5.2 What Is Digestion? 5.3 What Is Absorption? 5.4 What Happens to the Absorbed Nutrients? 5.5 What Are the Effects of Alcohol Consumption? 43 © 2023 Marshall Cavendish Education Pte Ltd 5.3 What Is Absorption? Learning Outcome(s) Explain how the structure of a villus, including the capillaries and lacteal, is suited for its function of absorption. 44 © 2023 Marshall Cavendish Education Pte Ltd Textbook Absorption Pages 85–86 Absorption is the process whereby digested food substances are absorbed into the body cells. Products of digestion such as simple sugars, fatty acids and amino acids are absorbed throughout the small intestine, especially the ileum Water and mineral salts are absorbed by the small intestine and colon. The small intestine absorbs most of this water before the food moves to the colon, where much of the remaining water is absorbed 45 © 2023 Marshall Cavendish Education Pte Ltd Textbook How is the small intestine adapted for absorption? Page 85 Adaptation Function Inner surface has numerous ﬁnger-like Increases surface area for absorption projections called villi The epithelium (wall) of the villus is one cell Provides a short diﬀusion distance thick for nutrients to pass through The cells of the epithelium have many Further increases surface area for microvilli absorption 46 © 2023 Marshall Cavendish Education Pte Ltd Textbook Page 85 Adaptation Function Each villus has many blood Capillaries allow blood to transport capillaries the absorbed glucose and amino acids away, in order to maintain a diﬀusion gradient Each villus contains a lacteal Allows the transport of absorbed fats away, so a steep diﬀusion gradient is maintained The epithelial cells contain many Mitochondria provide energy for the mitochondria active transport of nutrients into the villi 47 © 2023 Marshall Cavendish Education Pte Ltd Textbook Page 86 How does absorption take place in the small intestine? Glucose and amino acids are absorbed by diﬀusion into the blood capillaries of the villi Glucose and amino acids are also absorbed by active transport. This happens when there is a lower concentration of these digested food substances in the lumen of the small intestine than in the blood capillaries. Glycerol and fatty acids diﬀuse into the epithelium. Here they combine to form minute fat globules that enter the lacteals. 48 © 2023 Marshall Cavendish Education Pte Ltd Video Time! Food absorption in the small intestine 49 © 2023 Marshall Cavendish Education Pte Ltd Textbook Tech Connect – Capsule Endoscopy Page 87 In the traditional procedure, the doctor inserts a tube, with a light and a camera at its tip, into the patient’s stomach via the mouth. In the new technology, a patient swallows a capsule containing a camera, which takes pictures as it passes through the gut, and sends them to a computer. 50 © 2023 Marshall Cavendish Education Pte Ltd Textbook Page 87 What happens to undigested and unabsorbed matter? Undigested and unabsorbed matter is stored temporarily, in the rectum. It is then discharged as faeces through the anus (egestion). 51 © 2023 Marshall Cavendish Education Pte Ltd Living without a large intestine Some individuals suffer through diseases which result in them getting a total proctocolectomy — a removal of the large intestine. Consider the following questions: 1. Why is it possible for the large intestine to be completely removed but not the small intestine? 2. What side effects might one experience if their large intestine were to be removed? 3. How would patients deal with such side effects? 52 © 2023 Marshall Cavendish Education Pte Ltd Textbook Page 88 Does a camel store food in its hump? 53 © 2023 Marshall Cavendish Education Pte Ltd Chapter 5 Nutrition in Humans 5.1 What Is Nutrition? 5.2 What Is Digestion? 5.3 What Is Absorption? 5.4 What Happens to the Absorbed Nutrients? 5.5 What Are the Effects of Alcohol Consumption? 54 © 2023 Marshall Cavendish Education Pte Ltd 5.4 What Happens to the Absorbed Nutrients? Learning Outcome(s) State the function of the hepatic portal vein as the transport of blood rich in absorbed nutrients from the small intestine to the liver. State the role of the liver in: conversion of glucose to glycogen and vice versa, fat digestion, metabolism of amino acids and formation of urea, breakdown of alcohol, and the breakdown of hormones. 55 © 2023 Marshall Cavendish Education Pte Ltd Textbook Assimilation Page 88 The process whereby some of the absorbed nutrients are converted into new cytoplasm of used to provide energy After absorption, the blood in the villi is rich in nutrients. The blood capillaries unite to form larger blood vessels, which then unite to form the hepatic portal vein. The hepatic portal vein transports nutrients from the small intestine to the liver. 56 © 2023 Marshall Cavendish Education Pte Ltd Textbook Pages 88–89 Glucose after absorption In the liver, most absorbed sugars are converted into glycogen and stored. Some glucose is transported by the blood leaving the liver, and is distributed around the body to be used for energy during cell respiration. Excess glucose is transported back to the liver and stored as glycogen for use in the future. 57 © 2023 Marshall Cavendish Education Pte Ltd Textbook Page 89 Amino acids after absorption Amino acids that enter the cells are converted into new cytoplasm that is used for growth and repair of worn-out parts of the body. Amino acids are also used to form enzymes and hormones. In the liver, excess amino acids have their amino groups are removed and converted into urea. This is known as deamination. Urea is removed from the body in the urine. The remains of the deaminated amino acids are converted into glucose in the liver. 58 © 2023 Marshall Cavendish Education Pte Ltd Textbook Page 89 Fats after absorption Fats are absorbed into the lymphatic capillaries, which join to form larger lymphatic vessels. These discharge fats into the bloodstream. Blood carries the fats to all parts of the body, especially the liver. When there is enough glucose, fats are not broken down and are used to build protoplasm like cell membranes. When glucose is in short supply, fats are broken down to provide the energy needed for vital activities in the body. Excess fat is stored in adipose tissues beneath the skin and around the heart and kidneys. Adipose tissues protect organs by acting as shock absorbers. 59 © 2023 Marshall Cavendish Education Pte Ltd Textbook Let’s Investigate 5.3 Page 90 Aim: To investigate digestion and absorption of carbohydrates Discussion Assume that the Visking tubing represents a mammalian gut wall. (a) Explain your results in terms of digestion and absorption of carbohydrates in the mammalian gut. (b) Name two enzymes involved in carbohydrate digestion and state the part of the gut in which they can be found. (c) If the Visking tubing represents a portion of the mammalian gut, what would the distilled water represent? 60 © 2023 Marshall Cavendish Education Pte Ltd Concept Cartoon Textbook Page 89 Consider the following snacks: a 200-calorie snack of peanut butter and crackers a 200-calorie snack of french fries a 200-calorie snack of sugar-coated doughnuts Which snack can provide a quick boost of energy? What is your view? 61 © 2023 Marshall Cavendish Education Pte Ltd 1. Which character do you agree with? Why? 2. Which snack do you think would be more easily absorbed and assimilated? 3. Why are some of these snacks less healthy than others? 4. What impacts would the overconsumption of these unhealthy snacks have in the long run? 5. How effective are calories in measuring how good a kind of food is for you? 62 © 2023 Marshall Cavendish Education Pte Ltd Video Time! Why is the liver important? 63 © 2023 Marshall Cavendish Education Pte Ltd Textbook Functions of the Liver Page 91 Production of Bile Deamination of Amino Acids Regulation of Blood Glucose Concentration o The liver plays a key role in keeping the amount of glucose in the blood constant, especially after a heavy meal or during fasting. o The pancreas contains special groups of cells known as the islets of Langerhans which secrete the hormones insulin and glucagon into the bloodstream. Both insulin and glucagon together help to regulate the level of glucose in the blood. 64 © 2023 Marshall Cavendish Education Pte Ltd Textbook Breakdown of Hormones Page 92 o Hormones, after they have served their purpose, are broken down in the liver. Detoxification o Harmful substances may be absorbed into the blood from the gut. These substances (e.g. the food preservative benzoic acid) is made harmless by the liver cells. o Alcohol is also broken down by the liver. Alcohol can cause damage to the digestive system and slow down brain functions. o Liver cells contain an enzyme which breaks down alcohol to compounds that can be used in respiration, providing energy for cell activities. 65 © 2023 Marshall Cavendish Education Pte Ltd What Is a Hormone? A chemical substance produced in very small quantities by an endocrine gland. It is transported in the bloodstream to target organ(s) where it exerts its effect(s). Can influence the growth, development and activity of an organism. Are chemical messengers that help the various parts of the body to respond, develop and work together smoothly. Some glands produce only hormones, while other glands such as the pancreas produce both hormones and other secretions: o The pancreas produces pancreatic juice o The pancreas also contains special groups of cells known as the Islets of Langerhans which secrete the hormones insulin and glucagon into the bloodstream. o These hormones help to regulate the concentration of glucose in the blood. 66 © 2023 Marshall Cavendish Education Pte Ltd Video Time! What are insulin and glucagon? 67 © 2023 Marshall Cavendish Education Pte Ltd High blood glucose Low blood glucose Textbook Page 91 concentration concentration Pancreas detects this and produces insulin. Pancreas detects this change and produces glucagon. Insulin is transported in the blood to liver and muscle cells Glucagon is transported in the blood to the liver Insulin: Glucagon: o Makes cell membranes more permeable to glucose, allowing more glucose to o Increases blood glucose diffuse into the liver and muscle cells. concentration by stimulating the conversion of glycogen into glucose. o Stimulates liver and muscle cells to convert excess glucose into glycogen. o increases the use of glucose for respiration. 68 © 2023 Marshall Cavendish Education Pte Ltd Video Time! Toxic Substances that can be Broken Down by Liver Cells https://www.nagwa.com/en/videos/83713906124 2/ 69 © 2023 Marshall Cavendish Education Pte Ltd What are other functions of the liver? 70 © 2023 Marshall Cavendish Education Pte Ltd Group Work Outline the liver’s role in the regulation of blood glucose concentration. 71 © 2023 Marshall Cavendish Education Pte Ltd Activity Time! Can drinking alcohol be harmful? Try out the simulator below: − Set the difficulty to Absinthe − Mute the website tab − What do you notice about the simulation as more and more alcohol is consumed? − What are the real life implications of this for the driver and others on the road? Game simulation: https://www.y8.com/games/don_t_drink_and_drive_simulator 72 © 2023 Marshall Cavendish Education Pte Ltd Chapter 5 Nutrition in Humans 5.1 What Is Nutrition? 5.2 What Is Digestion? 5.3 What Is Absorption? 5.4 What Happens to the Absorbed Nutrients? 5.5 What Are the Effects of Alcohol Consumption? 73 © 2023 Marshall Cavendish Education Pte Ltd 5.5 What Are the Effects of Alcohol Consumption? Textbook Page 92 Learning Outcome(s) Outline the effects of alcohol consumption on the brain (e.g. increased reaction time, reduced self-control), the long-term effects of excessive consumption (e.g. liver disease and brain damage) and the social implications. 74 © 2023 Marshall Cavendish Education Pte Ltd Textbook Harmful Effects on the Digestive System Page 93 Alcohol stimulates acid secretion in the stomach. Excess stomach acid increases the risk of gastric ulcers. Too much alcohol may lead to cirrhosis of the liver Cirrhosis is a disease in which the liver cells are destroyed and replaced with ﬁbrous tissue, making the liver less able to function. Alcoholic cirrhosis may lead to haemorrhage in the liver, liver failure and subsequently, death. 75 © 2023 Marshall Cavendish Education Pte Ltd Video Time! Liver Cirrhosis https://www.youtube.com/watch?v=l-SBR7p7K-M&t= 76 © 2023 Marshall Cavendish Education Pte Ltd 7s Textbook Impacts on the Nervous System Pages 93–94 Depressant Alcohol slows down some brain functions. Its effects vary from one person to another. Reduced Self-control A person becomes carefree as alcohol takes away their self-control. They may do things that they may regret after the effects of alcohol have worn off. Effect on Reaction Time Slurred speech, blurred vision and poor muscular coordination may occur. People may be unable to move steadily. Their judgement deteriorates and they tend to underestimate speed. They may drive faster and with less caution, and their reactions become slower. Drunk drivers have a higher tendency to be involved in traffic accidents. 77 © 2023 Marshall Cavendish Education Pte Ltd Textbook Long-term Impacts on the Brain Page 94 Wet brain: A type of dementia caused by brain damage. Alcohol interferes with the absorption of vitamin B1 (thiamine) in the small intestine. Vitamin B1 is part of an enzyme needed to break down sugar to release energy for brain activities, e.g. in the conduction of nerve impulses. Shrinkage of brain volume: The brain becomes smaller (shown by the red portion) than normal, especially the region associated with memory and reasoning. Heavy consumption of alcohol during pregnancy may interfere with the development of the foetus’ brain, which may lead to lifelong physical, mental and behavioural problems. 78 © 2023 Marshall Cavendish Education Pte Ltd Textbook Social Implications Page 94 Some people may become addicted to alcohol and be unable to stop drinking until they are drunk, as their bodies become dependent on alcohol. Alcoholics may, o end up neglecting their work and families. o exhibit violent behaviour, especially towards family members. o be at a higher risk of committing crimes. 79 © 2023 Marshall Cavendish Education Pte Ltd Activity Time! What is the age restriction for alcohol consumption in Singapore? 80 © 2023 Marshall Cavendish Education Pte Ltd Video Time! What is liver disease? https://youtu.be/o-Kvlxyj43 I Stop at 3:52 min 81 © 2023 Marshall Cavendish Education Pte Ltd Chapter 6 Transport in Humans Biology Matters for GCE ‘O’ Level (3Ed) 82 © 2023 Marshall Cavendish Education Pte Ltd Is blood a pure substance or a mixture? Is blood a homogeneous liquid? 83 © 2023 Marshall Cavendish Education Pte Ltd High-altitude Training Textbook Page 97 Professional athletes sometimes train in high-altitude rooms. What are these rooms? They train in such rooms to help improve their performance. This has something to do with what is found in blood. What is it? How does it help? 84 © 2023 Marshall Cavendish Education Pte Ltd Chapter 6 Transport in Humans 6.1 What Are the Main Components of Blood? 6.2 What Are Blood Groups? 6.3 How Are Blood Vessels Adapted to Their Functions? 6.4 How Does Blood Circulate in the Human Body? 6.5 What Is Coronary Heart Disease? 85 © 2023 Marshall Cavendish Education Pte Ltd Learning Outcome(s) ∙ State the components of blood and their roles in transport and defence: − plasma: transport of blood cells, ions, soluble food substances, hormones, carbon dioxide, urea, vitamins, plasma proteins − red blood cells: haemoglobin for oxygen transport − white blood cells: phagocytosis, antibody formation and tissue rejection − platelets: fibrinogen to fibrin, causing clotting 86 © 2023 Marshall Cavendish Education Pte Ltd Textbook 6.1 What Are the Main Components of Blood? Page 98 87 © 2023 Marshall Cavendish Education Pte Ltd Textbook Plasma Page 99 What is the role Yellowish liquid in blood is plasma. of plasma in Contains mainly water transport? o Transports blood cells around the body o Transports excretory products (e.g. urea, amino acid) to excretory organs from removal o Transports substances (e.g. glucose, proteins, fats, salts, vitamins) o Transports nutrients from small intestines to other parts of the body o transports hormones from endocrine glands to target organs 88 © 2023 Marshall Cavendish Education Pte Ltd Textbook Red Blood Cells Page 99 Primary function: o to transport oxygen from the lungs to other parts of the body Red blood cells have features suited to perform this function efficiently. What are these features 89 © 2023 Marshall Cavendish Education Pte Ltd Red Blood Cells Textbook Page 99 Contains haemoglobin that can combine reversibly with oxygen. 90 © 2023 Marshall Cavendish Education Pte Ltd Textbook Red Blood Cells Page 99 Biconcave shape: to increase the surface area-to-volume ratio which increases the rate of diffusion of oxygen into and out of the cell. No nucleus: to make more space available for more haemoglobin 91 © 2023 Marshall Cavendish Education Pte Ltd Textbook Red Blood Cells Page 99 Flexible and can change into a bell-shaped structure so that they can move easily through narrow capillaries 92 © 2023 Marshall Cavendish Education Pte Ltd Challenge! You have learnt that plasma contains: o mainly water There is very little o blood cells oxygen found in plasma. Why is this so? o excretory products (e.g. urea, amino acid, carbon dioxide) o substances (e.g. glucose, proteins, fats, salts, hormone vitamins) 93 © 2023 Marshall Cavendish Education Pte Ltd High-altitude Training Textbook Page 100 High-altitude training increases the number of red blood cells and the amount of haemoglobin in the cells. How does an increase in haemoglobin level help an athlete? Equation for Respiration 94 © 2023 Marshall Cavendish Education Pte Ltd Let’s play a quiz on your personal learning device to review what you have learnt! Launch Kahoot! Quiz 6.1 95 © 2023 Marshall Cavendish Education Pte Ltd TB eBook Biology Connect Page 97 Watch the video and hear different views about high-altitude training. Does high-altitude training really make a difference in improving performance? What do you think? High-altitude Training 96 © 2023 Marshall Cavendish Education Pte Ltd Have you heard about the Bubble boy? David was born without white blood cells in his blood. The Bubble boy, David Vetter, suffered from severe combined immunodeficiency (SCID). Q: Why do you think David had to be inside a bubble because of his condition? 97 © 2023 Marshall Cavendish Education Pte Ltd Chapter 6 Transport in Humans 6.1 What Are the Main Components of Blood? 6.2 What Are Blood Groups? 6.3 How Are Blood Vessels Adapted to Their Functions? 6.4 How Does Blood Circulate in the Human Body? 6.5 What Is Coronary Heart Disease? 98 © 2023 Marshall Cavendish Education Pte Ltd Learning Outcome(s) ∙ State the components of blood and their roles in transport and defence: − plasma: transport of blood cells, ions, soluble food substances, hormones, carbon dioxide, urea, vitamins, plasma proteins − red blood cells: haemoglobin for oxygen transport − white blood cells: phagocytosis, antibody formation and tissue rejection − platelets: fibrinogen to fibrin, causing clotting 99 © 2023 Marshall Cavendish Education Pte Ltd Textbook White Blood Cells Page 100 ∙ There are two types of white blood cells, the phagocyte and lymphocyte 100 © 2023 Marshall Cavendish Education Pte Ltd Textbook Page 100 Functions of White Blood Cells 1. Engulf and destroy pathogens such as bacteria This process is known as phagocytosis. It is performed by the phagocytes. 101 © 2023 Marshall Cavendish Education Pte Ltd Textbook Functions of White Blood Cells Page 100 2. Produce antibodies Antibodies produced by lymphocytes can: o recognize and destroy pathogens o cause pathogens to clump together for easy ingestion by phagocytes o neutralize toxins produced by bacteria 102 © 2023 Marshall Cavendish Education Pte Ltd Textbook Platelets Page 101 Cytoplasm fragments Contain an enzyme that catalyses the conversion of fibrinogen to fibrin threads o Fribrin threads entangle with red blood cells to form blood clot that seals wound 103 © 2023 Marshall Cavendish Education Pte Ltd Textbook How Does Blood Clot? Page 101 104 © 2023 Marshall Cavendish Education Pte Ltd Textbook Organ Transplant and Tissue Rejection Page 102 Recall the role of white blood cells in the body’s immune system. During certain medical procedures that are meant to help a patient, such as organ transplant or blood transfusion, the immune system may recognise a donated organ or blood as foreign tissue and cause tissue rejection. To avoid tissue rejection, tissue matching is important. You will learn examples of this involving blood groups in the next lesson. 105 © 2023 Marshall Cavendish Education Pte Ltd Let’s play a quiz on your personal learning device to review what you have learnt! Launch Kahoot! Quiz 6.2 106 © 2023 Marshall Cavendish Education Pte Ltd Activity! 1. Research further on SCID using the internet. Find out if there is a cure or treatment for this condition. 2. Watch a video about David Vetter in Bubble Boy the internet to see what it was like for David to live in a bubble. 3. Share your thoughts on ClassPoint on some ethical issues involved in David’s situation. 107 © 2023 Marshall Cavendish Education Pte Ltd In some countries, a person’s blood group is stated on his or her identity card. What are some reasons for this? In Singapore, blood type used to be stated in a person’s identity card but is longer the case since quick blood group test is available. 108 © 2023 Marshall Cavendish Education Pte Ltd Chapter 6 Transport in Humans 6.1 What Are the Main Components of Blood? 6.2 What Are Blood Groups? 6.3 How Are Blood Vessels Adapted to Their Functions? 6.4 How Does Blood Circulate in the Human Body? 6.5 What Is Coronary Heart Disease? 109 © 2023 Marshall Cavendish Education Pte Ltd Learning Outcome(s) List the different ABO blood groups and describe all possible combinations for the donor and recipient in blood transfusions. 110 © 2023 Marshall Cavendish Education Pte Ltd What Are the Different Blood Groups? How many blood There are four main blood groups. They are blood groups: groups are there? A What are the B different blood AB groups? O 111 © 2023 Marshall Cavendish Education Pte Ltd What Are Antigens and Antibodies Textbook Page 103 of the Blood ? Blood antigens are special proteins found on the surface of red blood cells. Recall what you have learnt about antibodies in Section 6.1 A person has the same antigens on all his or her red blood cells. Antibodies are produced by the white blood cells. They are found in the plasma. 112 © 2023 Marshall Cavendish Education Pte Ltd Textbook Blood Antigen – Antibody Reaction Page 103 Antigens provoke an immune response involving antibodies. Certain types of antibodies react with certain types of antigens, causing agglutination or clumping. This can be fatal. 113 © 2023 Marshall Cavendish Education Pte Ltd Textbook Types of Antigens and Antibodies in Different Page 104 Blood Groups 114 © 2023 Marshall Cavendish Education Pte Ltd Questions on Blood Group Antigens o Which blood group has antigen A on its blood cells? Blood group A o Which blood group has antigen B on its blood cells? Blood group B o Which blood group has antigen A and antigen B on its blood cells? Blood group AB o Which blood group has no antigens on its blood cells? Blood group O 115 © 2023 Marshall Cavendish Education Pte Ltd Questions on Blood Group Antibodies o Which blood group has antibody a in the plasma? Blood group B o Which blood group has antibody b in the plasma? Blood group A o Which blood group has both antibodies a and b in the plasma? Blood group O o Which blood group has no antibodies a and b in the plasma? Blood group AB 116 © 2023 Marshall Cavendish Education Pte Ltd Textbook What Happens When Different Blood Groups Are Page 104 Mixed? 117 © 2023 Marshall Cavendish Education Pte Ltd Textbook Antibody Response in a Blood Transfusion Page 104 During a blood transfusion, if the donor’s blood cells have antigens that can react with the recipient’s antibodies, clumping of the blood occurs. This process, known as agglutination, is damaging as they can block blood vessels. 118 © 2023 Marshall Cavendish Education Pte Ltd Example A person with blood group B will have antigen B on his red blood cells. This antigen is going to cause a response in a person with antibody a in their plasma. People with blood group A and blood group O have antibody b in the plasma. Thus, they are unable to receive blood from a person with blood group B. 119 © 2023 Marshall Cavendish Education Pte Ltd Concept Cartoon Textbook Page 105 120 © 2023 Marshall Cavendish Education Pte Ltd Online Activity! https://educationalgames.nobelprize.org/educational/medicine/bloodtypinggame/ Blood Typing Game 121 © 2023 Marshall Cavendish Education Pte Ltd Textbook Page 103 Have you heard of someone who works as a phlebotomist? Can you guess what this person does? Would you consider this as a career? Why? 122 © 2023 Marshall Cavendish Education Pte Ltd Video Time! https://www.youtube.com/watch?v=mb39LgTs6v8 How Blood Is Processed at the Blood Bank 1) Why is donated blood separated into various components? 2) Who do you think would need a transfusion of: a) red blood cells b) platelets c) plasma 3) Why are white blood cells removed and not transfused into the patient? 123 © 2023 Marshall Cavendish Education Pte Ltd https://www.youtube.com/watch?v=bIGB8aooakE Video Time! Since olden times, people have been curious to know about how blood travels around the body. Some even had to pay the ultimate price for it! 124 © 2023 Marshall Cavendish Education Pte Ltd What Did Early Scientists Think of Blood? Galen: thought there were two types of blood and they Was Galen right? served different functions Explain why you thought that the liver and heart produced blood think so. which the organs used up William Harvey’s experiment: bandage was tight around the arm o arm below bandage became cool and pale while arm What did the above bandage became warm and swollen experiment bandage was loosened slightly show? o the blood from the arteries (deeper in the flesh than veins) could flow into the lower arm and the lower arm became warm and swollen 125 © 2023 Marshall Cavendish Education Pte Ltd Chapter 6 Transport in Humans 6.1 What Are the Main Components of Blood? 6.2 What Are Blood Groups? 6.3 How Are Blood Vessels Adapted to Their Functions? 6.4 How Does Blood Circulate in the Human Body? 6.5 What Is Coronary Heart Disease? 126 © 2023 Marshall Cavendish Education Pte Ltd Learning Outcome(s) ∙ Relate the structures of arteries, veins and capillaries to their functions. ∙ Describe the transfer of materials between capillaries and tissue fluid. 127 © 2023 Marshall Cavendish Education Pte Ltd Textbook Pages 106–107 Parts of the Circulatory System The circulatory system consists of the: heart blood vessels o arteries o arterioles o blood capillaries o venules o veins 128 © 2023 Marshall Cavendish Education Pte Ltd Textbook Structure and Function Page 108 ∙ In biology, structure is always related to function. ∙ The different types of blood vessels have structures that are adapted to their functions. 129 © 2023 Marshall Cavendish Education Pte Ltd Adaptations of Arteries o Thick muscular and elastic walls to withstand the high blood pressure of blood flowing within. o The elasticity helps the artery wall to stretch and recoil o The contraction and relaxation of the arterial walls to divert blood to certain organs at certain times (e.g. dilation of arterioles of the skin to divert blood to skin capillaries during thermoregulation) 130 © 2023 Marshall Cavendish Education Pte Ltd Adaptations of Veins ∙ The function of veins is to transported blood back to the heart. However, as blood that is in the vein has lower pressure and speed, it has a tendency to backflow. ∙ Veins therefore have valves to prevent backflow of blood. ∙ in the veins, blood flows more slowly and smoothly compared to in the arteries. Thus, the walls of veins are thinner than the walls of the arteries. 131 © 2023 Marshall Cavendish Education Pte Ltd Adaptations of Veins ∙ However, as blood that is in the vein has lower pressure and speed, it has a tendency to backflow. ∙ Veins therefore have valves to prevent backflow of blood. 132 © 2023 Marshall Cavendish Education Pte Ltd Challenge: Look at the micrograph. Identify the artery (A) and the vein (V). Give your reasons. 133 © 2023 Marshall Cavendish Education Pte Ltd Textbook Page 111 Let’s Practice 6.3 Q5 134 © 2023 Marshall Cavendish Education Pte Ltd What Could Happen When We Textbook Page 110 Sit for Too Long? ∙ When we sit for too long without much movement, pressure can build up in the veins of the lower limbs. This causes poor blood circulation and blood to pool in the legs. ∙ Skeletal muscles and movement are important to ensure blood returns to the heart. 135 © 2023 Marshall Cavendish Education Pte Ltd Video Time! https://www.youtube.com/watch?v=QJQ95XtJjiU 136 © 2023 Marshall Cavendish Education Pte Ltd Have you seen people who have red coloration on their skin? These permanent birthmark and can appear on their hands, faces or any parts of their bodies. They are What do you think causes the red colouration ? 137 © 2023 Marshall Cavendish Education Pte Ltd Chapter 6 Transport in Humans 6.1 What Are the Main Components of Blood? 6.2 What Are Blood Groups? 6.3 How Are Blood Vessels Adapted to Their Functions? 6.4 How Does Blood Circulate in the Human Body? 6.5 What Is Coronary Heart Disease? 138 © 2023 Marshall Cavendish Education Pte Ltd Learning Outcome(s) ∙ Relate the structures of arteries, veins and capillaries to their functions. ∙ Describe the transfer of materials between capillaries and tissue fluid. 139 © 2023 Marshall Cavendish Education Pte Ltd Recall! What is the role of blood capillaries? The role of blood capillaries is to facilitate exchange of The exchange of substances between blood and tissue cells in the body. substances occurs mainly by diffusion. What are the features of blood capillaries that are adapted to perform this role? Factors affecting diffusion are as follows: Recall factors that Temperature* affect diffusion to Surface area help you remember Diffusion distance the adaptations of Steep concentration gradient blood capillaries. *temperature does not matter in the human body because it is constant 140 © 2023 Marshall Cavendish Education Pte Ltd Recall! What are the features of blood capillaries that are adapted to perform this role? Features of blood capillaries: ∙ walls: partially permeable, one-cell thick ∙ vessels: tiny and numerously branched to Adaptations must ensure that: o increase the surface area for exchange ∙ surface area is maximised of substances ∙ diffusion distance is minimised o increase the total cross-sectional area ∙ concentration difference is maximised of the blood vessels, lowering the blood pressure and thereby slowing blood flow to give more time for exchange of substances 141 © 2023 Marshall Cavendish Education Pte Ltd Low Blood Speed and Pressure in Capillaries As capillaries are so numerous, if a cross-section is taken across all the capillaries and the total cross-sectional area compared to that of the artery, there would be an increase in total cross-sectional area as blood moves from artery to capillaries, thereby reducing the blood’s speed and pressure, giving more time for exchange of substances to take place. Cross-sectional area of artery Cross-sectional areas of all the capillaries in the network 142 © 2023 Marshall Cavendish Education Pte Ltd Summary of Adaptations of Capillaries To increase rate of exchange of substances, How is it achieved? capillaries need: Large surface area Numerous branches of capillaries Wall of capillaries made up of single layer of Short diffusion distance flattened cells Steep concentration Continuous blood flow through the capillaries gradient Note! Adaptations of the villus and the alveolus in chapters 5 and 7 respectively have similarities to that of the capillaries because they have similar function as surfaces for exchange of substances. 143 © 2023 Marshall Cavendish Education Pte Ltd How Are Substances Transferred Between Textbook Page 110 Capillaries and Tissue Fluid? What is tissue fluid? Tissue fluid: tissue colourless fluid that filled the fluid spaces between cells in tissue transport dissolved substances between blood capillaries and tissue cells 144 © 2023 Marshall Cavendish Education Pte Ltd How Are Substances Transferred Between Textbook Page 110 Capillaries and Tissue Fluid? What are some of the substances that are transferred from: blood to tissue fluid? tissue fluid to blood? 145 © 2023 Marshall Cavendish Education Pte Ltd What is this bulb device? What can input tube you use it for? How does this device output tube work? 146 © 2023 Marshall Cavendish Education Pte Ltd Video Time! https://www.youtube.com/watch?v=joN3AHc_BMs How can you relate the siphon pump to blood circulation? 147 © 2023 Marshall Cavendish Education Pte Ltd Chapter 6 Transport in Humans 6.1 What Are the Main Components of Blood? 6.2 What Are Blood Groups? 6.3 How Are Blood Vessels Adapted to Their Functions? 6.4 How Does Blood Circulate in the Human Body? 6.5 What Is Coronary Heart Disease? 148 © 2023 Marshall Cavendish Education Pte Ltd Learning Outcome(s) Describe the structure and function of the heart in terms of muscular contraction and the working of valves. Outline the cardiac cycle in terms of what happens during systole and diastole. Identify the main blood vessels to and from the heart, lungs, liver and kidneys. 149 © 2023 Marshall Cavendish Education Pte Ltd Textbook Double Circulation Page 112 ∙ Movement of blood in a double circulation: o From the heart to the lungs to the heart o From the heart to the rest of the body back to the heart ∙ In a double circulation, the blood has to pass through the heart twice in one complete circuit. Challenge: Why does blood need to make another stop at the heart (why not continue circulating through the organs once blood has been oxygenated at the lungs)? 150 © 2023 Marshall Cavendish Education Pte Ltd Textbook What Are the Main Page 120 Blood Vessels Through Which the Heart Pumps Blood? Through and from the heart o upper vena cava o lower vena cava o pulmonary vein o pulmonary artery o aorta 151 © 2023 Marshall Cavendish Education Pte Ltd Textbook What Are the Main Page 120 Blood Vessels Through Which the Heart Pumps Blood? Through and from the lungs o pulmonary vein o pulmonary artery 152 © 2023 Marshall Cavendish Education Pte Ltd Textbook What Are the Main Page 120 Blood Vessels Through Which the Heart Pumps Blood? Through and from the liver o hepatic artery o hepatic portal vein o hepatic vein 153 © 2023 Marshall Cavendish Education Pte Ltd Textbook What Are the Main Page 120 Blood Vessels Through Which the Heart Pumps Blood? Through and from the kidneys o renal artery o renal vein 154 © 2023 Marshall Cavendish Education Pte Ltd Textbook Page 121 Main Blood Vessels in the Human Body Challenge: What do you notice about the: pulmonary artery, pulmonary vein? 155 © 2023 Marshall Cavendish Education Pte Ltd Name the blood 1 vessels labelled 1 to 12. 2 7 3 8 4 9 5 10 12 6 11 156 © 2023 Marshall Cavendish Education Pte Ltd Video Time! https://www.youtube.com/watch?v=mYZXoD73 GO0 Watch the video. Give three key takeaways from this video. 157 © 2023 Marshall Cavendish Education Pte Ltd When you inflate a float, the air stays inside the In contrast, when you float even when you stop blow a rubber balloon pumping more air into it to a certain size, the air or when you leave the air will immediately inlet open. escape if you let go of Why do you the opening. think these happens? 158 © 2023 Marshall Cavendish Education Pte Ltd Chapter 6 Transport in Humans 6.1 What Are the Main Components of Blood? 6.2 What Are Blood Groups? 6.3 How Are Blood Vessels Adapted to Their Functions? 6.4 How Does Blood Circulate in the Human Body? 6.5 What Is Coronary Heart Disease? 159 © 2023 Marshall Cavendish Education Pte Ltd Learning Outcome(s) Describe the structure and function of the heart in terms of muscular contraction and the working of valves. Outline the cardiac cycle in terms of what happens during systole and diastole. Identify the main blood vessels to and from the heart, lungs, liver and kidneys. 160 © 2023 Marshall Cavendish Education Pte Ltd Textbook The Heart Page 113 Where is your heart located? How big is the size your heart? What is the function of the heart? 161 © 2023 Marshall Cavendish Education Pte Ltd The Structure and Textbook Page 114 Function of the Heart 1. Four chambers Two atria o right atrium o left atrium Two ventricles o right ventricle o left ventricle 162 © 2023 Marshall Cavendish Education Pte Ltd The Structure and Textbook Page 114 Function of the Heart 2. Median septum 3. Valves tricuspid valves bicuspid valves aortic valves (semi-lunar valves in the aorta) pulmonary valves (semi-lunar valves in the pulmonary artery) 163 © 2023 Marshall Cavendish Education Pte Ltd How Does a Valve Act Like a One-way Door? ∙ Blood should always move from the atrium to the ventricle and not the other way around. ∙ If the pressure is higher in one part of the heart compared to another, e.g. if pressure is higher in the atrium compared to the ventricle, blood will be forced from atrium to ventricle. ∙ However, the ventricular pressure would exceed the atrial pressure when the muscular walls of the ventricles are contracting to force blood out of the heart. ∙ Blood would naturally tend to move from the ventricle to the atrium, from area of higher pressure to lower pressure. ∙ The atrioventricular valves in the heart will be forced close when the pressure in the ventricles exceeds the pressure in the atria, thereby prevent blood from backflowing from ventricles into atria. 164 © 2023 Marshall Cavendish Education Pte Ltd TB eBook Biology Connect Page 114 Let’s imagine that we are red blood cells. Experience what it would be like to be pumped Journey through the heart. Through the Heart 165 © 2023 Marshall Cavendish Education Pte Ltd Video Time! https://www.youtube.com/watch?v=yb_bY1iy0wI Sheep Heart Dissection 166 © 2023 Marshall Cavendish Education Pte Ltd Textbook Structure of the Heart Pages 113, 115 7 8 10 5 9 6 1 2 11 12 3 4 167 © 2023 Marshall Cavendish Education Pte Ltd Textbook Hole in the Heart Page 116 ∙ The hole in the median septum will result in the mixing of oxygenated and deoxygenated blood, thereby reducing the concentration gradient for oxygen (and carbon dioxide) and reduces efficiency of gas exchange. ∙ This condition may cause problems such as shortness of breath, fatigue and heart failure. 168 © 2023 Marshall Cavendish Education Pte Ltd Post-lesson Activity! 1. Watch an animation of the action of the heart posted on Padlet. https://www.youtube.com/watch?v= ebzbKa32kuk 2. Share on ClassPoint what impresses you the most about the heart. 169 © 2023 Marshall Cavendish Education Pte Ltd Video Time! https://www.youtube.com/watch?v=QjEyjmNkN 3k What is an ECG machine? What do you notice about the green line at the top? What does this tell you about the heart’s activity? 170 © 2023 Marshall Cavendish Education Pte Ltd Chapter 6 Transport in Humans 6.1 What Are the Main Components of Blood? 6.2 What Are Blood Groups? 6.3 How Are Blood Vessels Adapted to Their Functions? 6.4 How Does Blood Circulate in the Human Body? 6.5 What Is Coronary Heart Disease? 171 © 2023 Marshall Cavendish Education Pte Ltd Learning Outcome(s) Describe the structure and function of the heart in terms of muscular contraction and the working of valves. Outline the cardiac cycle in terms of what happens during systole and diastole. Identify the main blood vessels to and from the heart, lungs, liver and kidneys. 172 © 2023 Marshall Cavendish Education Pte Ltd Systole and Diastole Systole = Contraction Diastole = Relaxation Atrial systole Atrial diastole => Atrium contracts => Atrium relaxes Ventricular systole Ventricular diastole => Ventricle contracts => Ventricle 173 © 2023 Marshall Cavendish Education Pte Ltd Textbook What Is the Cardiac Cycle? Page 116 ∙ The systole and the diastole are the two phases of the cardiac cycle. ∙ One cardiac cycle consists of one ventricular systole and one ventricular diastole 174 © 2023 Marshall Cavendish Education Pte Ltd Textbook Cardiac Cycle Page 116 Graph 175 © 2023 Marshall Cavendish Education Pte Ltd Textbook Cardiac Cycle Page 116 Graph 176 © 2023 Marshall Cavendish Education Pte Ltd Textbook Cardiac Cycle Page 116 Graph 177 © 2023 Marshall Cavendish Education Pte Ltd Textbook Cardiac Cycle Page 116 Graph 178 © 2023 Marshall Cavendish Education Pte Ltd Textbook Cardiac Cycle Page 116 Graph 179 © 2023 Marshall Cavendish Education Pte Ltd Textbook Cardiac Cycle Page 116 Graph 180 © 2023 Marshall Cavendish Education Pte Ltd Challenge! The graph below shows the pressure changes in the left ventricle. Sketch the graph to show the pressure changes in the right ventricle. 181 © 2023 Marshall Cavendish Education Pte Ltd Do heart cells need oxygen and nutrients? Where do they get the nutrients from? 182 © 2023 Marshall Cavendish Education Pte Ltd Chapter 6 Transport in Humans 6.1 What Are the Main Components of Blood? 6.2 What Are Blood Groups? 6.3 How Are Blood Vessels Adapted to Their Functions? 6.4 How Does Blood Circulate in the Human Body? 6.5 What Is Coronary Heart Disease? 183 © 2023 Marshall Cavendish Education Pte Ltd Learning Outcome(s) Describe coronary heart disease in terms of the occlusion of coronary arteries and list the possible causes, such as unhealthy diet, sedentary lifestyle and smoking, stating the possible preventative measures. 184 © 2023 Marshall Cavendish Education Pte Ltd Video Time! https://www.youtube.com/watch?v=dwp9t-lGou0&t=2 5s What Happens During a Heart Attack? 185 © 2023 Marshall Cavendish Education Pte Ltd Textbook What Happens During a Heart Attack? Page 122 186 © 2023 Marshall Cavendish Education Pte Ltd Textbook What Are the Causes of Coronary Page 122 Heart Diseases? 187 © 2023 Marshall Cavendish Education Pte Ltd smoking Textbook Pages 123–124 What Are the Risks Unhealthy diet: a diet Factors of Heart high in cholesterol, Disease? saturated fats and salt What Can We Do to Genetic Reduce the Risks of factor Getting Coronary Heart Disease? Age 188 © 2023 Marshall Cavendish Education Pte Ltd Sedentary lifestyle Textbook Page 125 Let’s Map It 189 © 2023 Marshall Cavendish Education Pte Ltd Let’s play a quiz on your personal learning device to review what you have learnt! Launch Kahoot! Quiz 6.3 190 © 2023 Marshall Cavendish Education Pte Ltd

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