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3/29/10 4:08 PM Page 43 Home B I G IIDDEEAA S 3.0 Quit Your health depends on the effective functioning of your interdependent organ systems. Do you think these people are experiencing stress? physical mental If you have ever experienced any kind of stress, you would know from your natural response to it that your organ systems work together as a whole. In other words, your organ systems are interdependent. For example, one of the immediate effects of stress is that your muscles become tense. This can trigger the heart, part of your circulatory system, to beat faster, so it pumps blood more quickly to the surface of the skin. As a result, you feel warmer or even flushed. Tense muscles over a period of time can also lead to aches, pains, and exhaustion. Scientists have collected much experimental evidence that your reaction to stress affects your health in many ways. Some forms of stress, such as doing something exciting or trying out a new game, can be fun and thrilling. This stress can help prepare your body to perform at its best. Other forms of stress can be unpleasant, such as being nervous in new surroundings or situations. Your reaction to stress can cause nausea or stomach pain, or result in emotional problems. Interdependence of systems is viewed in a broader way in Indigenous Knowledge. Good health is when your mind, heart, body, and spirit are in balance (mental, emotional, physical, and spiritual harmony). See Elder Velma Goodfeather’s message on page 58. t io emo nal 01-SK8-Unit1C s p irit u al 3.1 A Look Inside How do you feel when you are tense? What about when you are relaxed? What are the physical, mental, emotional, and spiritual effects when you feel tense or relaxed? Try the exercises on the next page to find out. ©P The medicine wheel indicates the connections and interactions between mental, emotional, physical, and spiritual aspects of a person’s being. There are many ways of representing the medicine wheel. Unit 1 Cells, Tissues, Organs, and Systems 43 01-SK8-Unit1C 3/29/10 4:08 PM Page 44 Home A 䉴 Sit so that you feel comfortable. Close your eyes and breathe slowly and rhythmically. Focus your attention on the sound of your breathing. Now, curl the toes of your left foot as tightly as you can. Hold for 3 s, then slowly let them relax. Slowly draw your foot upward, hold for three seconds, and then let it down to the floor again. Keep breathing slowly. Now, repeat this with your right foot. C Quit Push your belly out as far as you can, and hold for 3 s. Pull it in as far as you can, hold for 3 s, then relax. Take slow, rhythmical breaths. Pull your shoulders up toward your ears as if you were shrugging. Hold for 3 s, then relax. Keep breathing slowly. B䉱 Tighten the muscles in your left leg and hold for 3 s. Then, relax your leg. Keep breathing slowly. Repeat this with your right leg. D 䉱 Clench your left hand in a tight fist, hold for 3 s, then relax. Stretch your fingers apart as far as you can, hold for 3 s, then relax. Repeat with your right hand. E 䉴 䉴 Push your lips out and squeeze your eyes shut as tightly as you can. Hold for 3 s, then relax. Open your eyes and mouth as wide as you can—as if you were screaming silently. Hold for 3 s, then relax. 44 3.0 Your health depends on the effective functioning of your interdependent organ systems. ©P 01c_un01_sci8_sk_2p.qxp 3/15/11 11:02 AM Page 45 DE Home VE Quit LOP How Your Body Is Organized Many parts of your body were involved in the exercises you just completed. These included your skin, your bones, your heart, your lungs, your mouth, and your stomach. What other examples can you think of? Think back to Health Education and Science classes that you did in earlier years. When scientists investigate how your body works, they find that none of your body parts functions on its own. Each part is an organ, a particular arrangement of tissues that has a special function. A group of organs form a body system, called an organ system. The organs that make up each organ system work together to perform a certain task or function. Scientific studies allow a complex function to be broken down into the simpler workings of its parts. Each part must work well for the function to work well. For example, when you eat an apple, the organs of your digestive system work together to break down the food to supply your body with the energy and nutrients you need to survive. Afterward, your digestive system helps your body remove any unused material as waste. The digestive process allows the cells in your body to get the energy they need and eliminates harmful waste materials. The following tables describe some of your body’s organ systems. heart Circulatory System Structures Function Factors That Help Functioning heart, blood, arteries, veins • transport oxygen, food, and other substances throughout the body • transport some wastes to other organs for elimination • defend the body against diseases • connect all other organ systems • arteries that are clear of cholesterol • exercise Circulatory System Red blood cells ©P arteries = red veins = blue Unit 1 Cells, Tissues, Organs, and Systems 45 01-SK8-Unit1C 3/29/10 4:08 PM Page 46 Home Respiratory System nose Quit Structures Function Factors That Help Functioning nose, mouth, trachea, bronchi, lungs • transport oxygen from the outside air to the blood • transport carbon dioxide from the blood to the outside air • keep structures clear of harmful pollutants (such as tar from cigarette smoke) • keep free from colds mouth trachea lungs bronchi Digestive System mouth Structures Function Factors That Help Functioning mouth, esophagus, stomach, liver, intestines • break down food pieces into much smaller pieces (particles) so they can be absorbed and transported throughout the body • remove unused materials from food out of the body as waste • balanced diet • water esophagus liver stomach intestines The digestion of food begins in your mouth. 46 3.0 Your health depends on the effective functioning of your interdependent organ systems. ©P 01-SK8-Unit1C 3/29/10 4:08 PM Page 47 Home Quit Nervous System Structures brain Function Factors That Help Functioning brain, • co-ordinate and control the spinal cord, actions of all organs and eyes, organ systems ears, and other • detect, process, and respond sense organs to changes in external and (hand, nose, etc.) internal environment • enough rest • no stimulants or depressants spinal cord nerve The brain controls your nervous system. Excretory System kidney Structures Function Factors That Help Functioning kidneys, bladder, lungs, skin • remove chemical and gaseous wastes from the blood • water • balanced diet kidney bladder ©P Unit 1 Cells, Tissues, Organs, and Systems 47 01-SK8-Unit1C 3/29/10 4:08 PM Page 48 Home Quit Working Together for Health info BIT A Close Association Most people know that drinking alcohol when you are pregnant can harm your baby. But do you know why this happens? When a pregnant woman has an alcoholic drink, the alcohol passes from the mother into the unborn baby’s (fetus’s) bloodstream. Once inside the fetus, the alcohol can damage or destroy developing cells, including brain and spinal cord cells. The effects of this damage can include birth defects such as odd facial features, growth problems, and learning and behaviour problems. All your organ systems work together as a single unit for a common purpose: to support and maintain your life. This idea of working together as a unified, purposeful unit goes even deeper than systems. Each of your body’s systems contains organs. The organs that make up each system work together to perform a certain task or function. For example, the organs that make up your respiratory system work together to provide your body with the oxygen it needs, while ridding it of carbon dioxide. All of your organs support and maintain the healthy functioning of the system of which they are a part. The organs work in harmony for a healthy system. As you already learned, there are four types of tissues in humans and each human organ is made up of a group of tissues that work together. For example, your heart is made up of connective tissue (to hold its shape together), muscle tissue (to help it to move), and nerve tissue (to co-ordinate its movement). Different organs are composed of different kinds and amounts of tissues. It all depends on the role (or function) that the organ serves. Examples in animals Examples in plants Cells are the building blocks of all organisms. Tissues are clumps of similar cells working together in the same way. Organs are groups of tissues working together. brain shoot system cell = an individual unit of life tissue = a group of specialized cells organ = a group of tissues that perform a special function Body systems are made up of these three types of structures. 48 Systems are groups of organs working together. nervous system nerves root system Cells form tissues, which form organs. Every tissue in your body is made up of a group of smaller units, the cells. These cells work together for a particular function and each kind of cell suits its role in the body. For instance, muscle cells can stretch and snap back into shape. Cells are the smallest known functioning units of life. That is why scientists say that the cell is the most fundamental or basic unit of all living things. 3.0 Your health depends on the effective functioning of your interdependent organ systems. ©P 01-SK8-Unit1C 3/29/10 4:08 PM Page 49 Home Quit 1 a) Which of your organ systems were you aware of during the stress-relieving exercises you did at the beginning of this section? b) Which of your organ systems do you think were actually involved during the exercises? Provide details to support your answer. 2 Demonstrate understanding of the relationship among these terms: organ system, organ, tissue, and cell. Use words, diagrams, flow charts, or a combination of these to communicate your ideas. 3 Re-examine the organ system diagrams on pages 45–47. a) Does any one system seem to be more important than any of the others? Explain your answer. b) Do you think you could stay healthy if any of these systems were damaged, diseased, or missing? Why or why not? c) For one of the systems, suggest another factor that might affect the way it functions. d) What does the title “Working Together for Health” mean to you? 3.2 Close-up of the Circulatory System Following are some early ideas about the circulatory system and its main organ, the heart. Today, after about 350 years of investigation, we know that only one of these early ideas is accurate. One is partially accurate. The rest have been shown to be incorrect. Do you know, or can you figure out, which is which? ©P Unit 1 Cells, Tissues, Organs, and Systems 49