End of chapter exercises Problem 1: The following diagrams show the heart during the cardiac cycle. The arrows represent the flow of blood. Study the diagrams and answer the questions that follow: Figure 1 1. Identify the structures labelled A and B respectively. 2. Name and explain what happens in each of the phases of the cardiac cycle represented in: 1. Diagram I 2. Diagram II 3. Diagram III Answer 1:TODO Problem 2: Loss of a lot of blood, vomiting and diarrhoea often causes a decrease in blood volume. As a result, blood cannot move normally around the body, as blood vessels are not completely
full. The tissues do not get enough blood, leading to possible death of cells and hence damage to organs. 1. Explain why severe vomiting and diarrhoea would cause a decrease in the blood volume. 2. What is the relationship between blood volume and blood pressure? Answer 2:TODO Problem 3: Read the passage below and then answer the questions based on it. When the ventricles of the heart pump blood into the arteries, the pressure of the blood in the arteries is high. This is called systolic pressure (average 120 mm Hg). When the heart muscle relaxes, the pressure in the arteries is much less. This is called diastolic pressure (average 80 mm Hg). The average blood pressure of a healthy person is 120 over 80. It is normal for a person's blood pressure to differ slightly from the average. If blood pressure is too high or too low there is medication that can be used to control this. High blood pressure is called 'hypertension' and low blood pressure is called 'hypotension'. There are several contributing factors to heart disease, namely hypertension, strokes, lack of exercise, smoking, rich fatty diets, obesity and diabetes. Research has shown that 25% of the South African population suffer from hypertension and that this is on the increase. The treatment for hypertension is expensive and has a great impact on the health system and on the economy. 1. Explain what causes the pressure in the arteries to rise and fall. 2. Why is it essential that blood pressure in the capillary vessels be much lower than that in the artery? 3. List THREE reasons why heart disease is on the increase in South Africa. 4. Suggest ONE way in which the government could reduce the number of people with heart disease. Answer 3:TODO
Problem 4: Study the diagrams which show two cross-sections of mammalian blood vessels and answer the questions that follow: Figure 2 1. Which vessel, A or B is the artery? 2. Provide TWO reasons for your answer to the previous question. 3. Which vessel carries blood at low pressure? 4. Provide an explanation for your answer to the previous question. 5. Identify the parts numbered 1 to 4. 6. How do capillaries differ from larger blood vessels? 7. In which vessel, A or B would you expect to find valves? 8. What is the function of the valves in the previous question? 9. Name the blood vessel that: 1. carries deoxygenated blood from the heart to the lungs 2. carries oxygenated blood from the heart for systemic circulation 3. carries blood from the digestive system to the liver Answer 4:TODO Problem 5:
Study the diagram of the lymphatic system and answer the questions that follow: Figure 3 1. Name the components of the lymphatic system. 2. Identify the: 1. blood vessel numbered 3
2. duct numbered 4 3. structure numbered 6 3. Name TWO factors that assist movement of the lymph fluid. 4. State FOUR functions of lymph in the human body. Answer 5:TODO Problem 6: Multiple-choice questions 1. The left side of the heart 1. transports deoxygenated blood to the lungs 2. is more muscular than the right-hand side 3. has a built in pacemaker 4. is a mixture of oxygenated and deoxygenated blood 2. Angina is 1. a panic attack caused by the release of too much adrenalin 2. a fatal heart attack 3. a serious heart cramp caused by a lack of oxygen in the cardiac muscles 4. the result of a clot in the blood vessels going to the brain 3. The stage in the cardiac cycle when the blood is pumped into the aorta and the pulmonary artery is 1. atrial systole 2. ventricular diastole 3. general diastole 4. ventricular systole 4. The valve between the left ventricle and the left atrium of the heart is called the
1. mitral valve 2. tricuspid valve 3. aortic semi-lunar valve 4. pulmonary semi-lunar valve 5. The accompanying graph indicates that changes in adrenalin secretion and the pulse rate, before, during (0 to 10 minutes) and after a cigarette was smoked. Use the given graph to indicate which one of the following deduction is a valid interpretation of the graph. Figure 4 1. Smoking directly causes an increase in the basal metabolic rate. 2. The cardiac muscles relax during smoking. 3. Smoking directly stimulates the pulse rate. 4. There is a no relationship between adrenalin secretion and pulse rate
Explain WHY there is a relationships between smoking and adrenalin secretion Answer 6: 1. TODO 2. TODO 3. TODO 4. TODO 5. TODO Problem 7: Study the accompanying diagram of the ventral view of the external structure of the heart and answer the questions that follow.
Figure 5 1. Label parts numbered 1, 2, 7, 8.2 and 9.2 2. What type of blood (oxygenated or deoxygenated) is transported by blood vessels 1, 3 and 6? 3. What possible danger to human health exists if the lumen of structure 4 is obstructed with a thick layer of cholesterol 4. Discuss what happens during ventricular systole in the cardiac cycle. Answer 7:TODO Problem 8: Study the diagrams below illustrating the structure of different types of blood vessels. Graph A shows the average blood pressure in different blood vessels in the human body, while graph B indicates the rate of blood flow in the different blood vessels.
Figure 6 Tabulate three structural differences between an artery and a vein. Answer 8: Artery Vein thick muscle wall Round in cross section No valves, except bases of pulmonary artery and aorta Thin muscle wall Flatter in cross section Semi-lunar valves present at regular intervals
Table 1 Max 5 if not done on a table: Study graph B and give a reason why the rate of blood flow in the capillaries is very low. What is the systolic and diastolic pressure in the aorta? (graph A) Problem 9: The accompanying diagram represents the basic human blood circulation. Study the diagram and answer the questions.
Figure 7 Name the chamber of the heart illustrated as R and T. Name the arteries indicated as I and K. (organ C is the liver and organ E is the kidney) Name the vein indicated as J. Answer 9:TODO Problem 10: Answer the following questions with a word or phrase that corresponds to the description given. 1. The membrane surrounding the heart. 2. The valve situated between the left atrium and left ventricle. 3. The phase in the cardiac cycle when the atria contract. 4. The name of the artery taking deoxygenated blood to the lungs. 5. The blood circulatory system that supplies the heart muscle with oxygenated blood. 6. The disorder / condition that results from a blockage in a blood vessel in the brain. 7. The instrument used to measure blood pressure. 8. The blood system that supplies oxygen to body cells 9. The structure that separates the left and right sides of the heart. 10. The ability of the heart to contract at its own inherent rhythm. 11. The layer found on the inside of veins. 12. The blood vessel connecting the stomach and intestine to the liver. 13. Veins that have lost their elasticity and form small sacs of blood. 14. The smallest blood vessels in the body. 15. The pacemaker of the heart Answer 10:TODO