Module 8 Intro

Module 8—Circulation, Immunity, and Excretion

Module Summary

In this module you explored circulation, immunity, and excretion. The Big Picture connected these three body systems with the functioning of a water treatment plant. You explored the circulatory system in the first four lessons. Like a water treatment plant, the mechanics of a circulatory system include pumps, valves, tubing, and fluids. The primary structures of the circulatory system are the heart, veins, arteries, capillaries, and blood.

As you worked through each lesson you discovered how blood moves through the body, technologies related to the circulatory system, the components of blood, and how the circulatory system exchanges matter and energy with the environment.

By participating in a virtual dissection of a sheep’s heart, you were able to identify structures of the heart and map the flow of blood of pulmonary and systemic circulation. You explored the components and function of components in the blood—hemoglobin, plasma, and platelets.

Blood is a multifaceted component of your circulatory system that transports nutrients, gases, and wastes, contains cells for immunity, and has the ability to clot if you are injured. Energy flow is also maintained via the circulatory system. The ability for blood to absorb heat and the design of your network of blood vessels allows heat to be transferred or conserved in order to maintain body temperature. You also explored the importance of blood pressure as a mechanism to control the exchange of matter and as a measure of health.

In Lessons 5 and 6 you explored how your body deals with invading pathogens. As a water treatment plant removes harmful substances from tap water, your immune system also destroys harmful substances. You further explored the role of blood in immunity and you were introduced to the lymphatic system. Your body has three lines of defence against invading pathogens: physical/chemical barriers, cell-mediated response, and antibody mediated response.

Through a virtual blood typing activity, you discovered that blood type is dependent on antigens and antibodies. The wrong type of blood transfusion would create an immune response.

In the remaining lessons of this module you explored the excretory system. This is your body’s filtration system. Before tap water ends up in your glass, water has undergone several filtration processes to remove waste. Similarly, as blood cycles through your body, it is continually filtered by the kidneys. You studied the major structures of the kidney by following a virtual kidney dissection.

The nephrons were a major focus of the excretory system. As you investigated the structures of the kidney, you also examined how the nephrons regulate homeostasis by maintaining blood composition and ridding the body of wastes. You specifically looked at three processes occurring in successive portions of the nephron that form the waste products of urine: filtration, reabsorption, and secretion.

Lastly, you explored the role of the kidneys in maintaining the water-salt balance in the body. Via hormones, aldosterone, and ADH, electrolytes and osmotic pressure are controlled. Altering the permeability of the nephron to water and sodium ions helps to maintain homeostasis. You explored how urinalysis can be used to diagnose conditions such as diabetes mellitus. Technology, such as dialysis, has been developed to help people with kidney disorders. This technology mimics the filtration of blood across a semi-permeable membrane.

Each of the three systems studied in this module is dependent on the other ones. Without blood, the kidneys would have nothing to filter, the heart would have nothing to pump, and you would have no immunity. You would cease to exist as a living human being.

Without a heart, blood could not circulate, would not be filtered by the kidneys, would not be able to find pathogens, and would not transfer nutrients or gases. You would cease to exist.

Without kidneys your blood would remain unfiltered, and toxins would build up and inhibit the function of cells in the heart. You would cease to exist. There is a definite pattern. Homeostasis in your body hinges on the interdependence and health of all body systems.

Now that you have completed the lessons in this module, you will complete a module assessment project. In the module project you will have the choice between three extended responses. You will choose between investigating the circulatory system, the immune system, or the excretory system. You will also complete a final question that ties the three systems together. Once you have completed this module project, you will go to the Unit D Assessment.

Module Project

You will complete one of the three extended responses and a final question that ties together the three systems you studied. The purpose of an extended response is to help you take a closer look at a specific area of study. In this case you will choose between investigating the circulatory system, the immune system, or the excretory system. You may choose an assignment because you feel you have a stronger grasp of the content or you may choose an assignment because you feel you would benefit from a further study of that particular body system. The extended response activities allow you to further explore each body system. In the Unit Assessment you will build upon these module projects by pursuing an in-depth inquiry into the interdependence of your body systems in maintaining homeostasis.

Circulation

In this investigation you will explore the heart, related technology, and its function in the circulatory system. Your response may be presented as a written report, a diagram, a flow chart, a podcast, or in another format you have discussed with your teacher.

1. a) Draw a cross-sectional sketch of the human heart and label all of the chambers, valves, and major blood vessels that take blood into and away from the heart. (10 marks)
   
   b) Use a flow chart or illustration to trace the flow of blood through the heart. Start with the blood in the inferior vena cava, and end with blood entering the aorta. Include all of the chambers, valves, and major blood vessels that take blood into and away from the heart. (6 marks)
   
   c) Describe how you would use a stethoscope to determine damage to the aortic semilunar valve and damage to the left atrioventricular valve. Provide details, including what you would expect to hear and when in the cardiac cycle you would hear this particular sound. (4 marks)
   
   d) Explain what is meant by the term pulse. (2 marks)

Immunity

In this investigation you will explore the immune response to an organ transplant. Your response may be presented as a written report, a diagram, a flow chart, a podcast, or in another format you have discussed with your teacher.

1. Explain the immune response that resulted in tissue rejection of early heart transplants. (4 marks)
   
   
2. Research the term immunosupression. Compare how the immune system would respond in a transplant patient given immunosuppressive drugs with a patient not given these drugs. (8 marks)

Excretion

In this investigation you will look at a disease of the kidney and the damage it will cause. Your response may be presented as a written report, a diagram, a flow chart, a podcast or in another format you have discussed with your teacher.

Use the information below to answer the next questions.

1. a) Explain how glomerular disease (glomerulonephritis) can result in high blood pressure and why high blood pressure can do further damage to the kidneys. (3 marks)
   
   b) Explain why the urine of a healthy person does not contain protein or red blood cells, and describe how protein and red blood cells enter the urine of a person who has glomerulonephritis. (4 marks)
   
   c) Explain how the hormone aldosterone raises blood pressure. (3 marks)
   
   d) Define the term dialysis and describe the movement of dissolved substances. (3 marks)
   
   e) Using a diagram or a sketch, explain how hemodialysis (artificial kidney) is used to purify the blood of a person who has end-stage renal disease. (6 marks)
   
   f) Describe the impact on the life of a person who must undergo hemodialysis. (4 marks)

Final  Question

You have been exposed to the German measles but luckily your inoculations (shots) are up to date. Your point of contact with the virus was the alveoli of the respiratory system. Trace from that point the movement of the virus through the circulatory system by naming and describing the major blood vessels and the chambers of the heart.

Describe how the immune system recognizes and attacks the foreign proteins of the virus. Describe how the virus is broken down and removed by the excretory system.

This path can be described or illustrated through a text or graphic response.