Instructor s Guide. Films for the. Humanities & Sciences i A Wealth of Information. A World of Ideas.

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1 i A Wealth of Information. A World of Ideas. Instructor s Guide The Human Body: How It Works Introduction This program is part of the nine-part series The Human Body: How It Works. The series uses physiologic animations and illustrations, microscopic imaging, expert commentary, and footage of the body in motion to provide a thorough overview of the amazing human machine. The series includes: Cells, Tissues, and Skin The Immune System Human Development and the Reproductive System The Respiratory System The Circulatory System The Skeletal and Muscular Systems Digestion and Nutrition The Endocrine System The Nervous System and the Senses Topics Chapter 1: Why Do We Breathe? The program begins with an introduction to cellular respiration and the production of ATP. Also covered: Lactic acid fermentation. Chapter 2: Anatomy of the Respiratory System This section details the parts and functioning of the three regions of the respiratory tract. Viewers are guided from initial intake of air through the nose all the way to the alveoli, where gas exchange occurs. Also covered: The pleura. Copyright

2 Chapter 3: The Diffusion of Gas Molecules Here viewers learn three different factors that affect oxygen diffusion: reduced surface for gas exchange, reduced rate of oxygen entering the blood, and thickness of the diffusion barrier. Also covered: Fick s Law. Chapter 4: How Do We Breathe? The diaphragm and intercostal muscles are identified in this section as key components in the mechanics of breathing. The narrator explains how bulk flow, and the actions of pressure and volume in and around the lungs, keeps air moving in and out. Also covered: Boyle s Law. Chapter 5: Preventing Lung Collapse This chapter describes some factors in keeping the lungs inflated: negative pressure in the pleural cavity, the production of surfactants on the inner surface of the alveoli, and the dead air remaining in the lungs after exhalation. Chapter 6: Meeting Changing Oxygen Demands The role of the brain in respiration is presented here, as different types of chemoreceptors signal specialized neurons to increase oxygen intake when necessary. Also covered: The respiratory conditions hypoxia and high altitude pulmonary edema (HAPE). Learning Objectives Students will learn The parts and functions of the upper and lower respiratory tracts The functioning of the alveoli and pleura How the diaphragm and intercostal muscles function in inhalation and exhalation The processes of cellular respiration, lactic acid fermentation, gas exchange, diffusion, and bulk flow Factors affecting oxygen diffusion How the production of dead air, alveolar surfactants, and negative pressure in the pleural cavity keep the lungs from collapsing How the brain stem, cerebral cortex, specialized neurons, and chemoreceptors work together in respiration How the respiratory system adapts to keep muscles energized during intense exercise What occurs when people contract pulmonary edema, HAPE, and hypoxia Copyright

3 Vocabulary ATP: Adenosine triphosphate, a molecule that stores and transfers energy used by the cells for metabolism. ATP is produced during cellular respiration. alveolus (plural is alveoli): A tiny air sac found in the lung; this is where gas exchange occurs. An alveolus is about one one-hundredth of an inch in diameter. bronchioles: Small sub-branches of bronchi that lead to the alveolar ducts. bronchus (plural is bronchi): Also called a bronchial tube, it is a branch of the trachea that conveys air to the lungs. bulk flow: A term describing how substances such as air move from areas of higher concentration to lower concentration, and how air is moved in and out of the lungs. cellular respiration: The process whereby nutrients in food molecules are broken down to produce ATP. In so doing, waste products of carbon dioxide, water, and heat are formed. Oxygen must be present for cellular respiration to occur. central chemoreceptors: Specialized nerve cells located in the brain stem that monitor carbon dioxide levels. If levels rise, these stimulate the brain stem to increase respiration to eliminate the excess carbon dioxide. cerebral cortex: A part of the brain that responds to changes in the body s activity by signaling the brain stem to increase tidal volume and breathing rate. cilia: Hair-like projections found in the nasal cavity which catch small inhaled particles and move them to the throat to be swallowed. dead air: Air that remains in the lungs after exhaling, that helps to keep the lungs inflated. It has a lower oxygen content than that of freshly inhaled air. diaphragm: A band of muscle and connective tissue that separates the chest cavity from the abdominal cavity. diffusion: The process that allows molecules of oxygen and carbon dioxide to be transferred during gas exchange. The molecules move from areas of high pressure in the alveoli to areas of low pressure in the pulmonary capillaries until they reach equilibrium. Copyright

4 epiglottis: A small piece of cartilage at the back of the tongue that keeps swallowed food and liquid from entering the trachea. expiratory neurons: Neurons that extend down the spinal cord to connect with other neurons to carry signals to the diaphragm and intercostal muscles. Expiratory neurons fire when it s necessary to exhale more deeply, as during strenuous activity. Fick s Law: One of two laws derived by 19th-century scientist Adolf Fick governing the rate of diffusion of a gas across a fluid membrane. For instance, someone with damaged lung tissue will have a harder time breathing because the decreased lung surface area decreases the rate of oxygen diffusion. Fick s Law also explains why a drop in air pressure at high altitudes reduces the rate at which oxygen enters the blood. (Fick is also credited with creating the first set of contact lenses.) gas exchange: Respiration; the process whereby oxygen is transferred to the blood during inhalation, and carbon dioxide is transferred from the blood during exhalation. This transfer occurs between the alveoli and the pulmonary capillaries. high altitude pulmonary edema (HAPE): A condition in which fluid from the pulmonary capillaries leaks in the interstitial and alveolar spaces. This occurs at high altitudes due to insufficient oxygen in the blood. hypoxia: A condition in which reduced oxygen pressure decreases oxygen levels in the blood, causing fatigue, headache, dizziness, and other symptoms. Occurring at high altitudes, it can be a precursor to potentially lethal altitude sickness. inspiratory neurons: Neurons that extend down the spinal cord to connect with other neurons to carry signals to the diaphragm and intercostal muscles. The firing of inspiratory neurons causes us to inhale. intercostal muscles: Muscles between the ribs that aid the diaphragm in getting air in and out of the lungs. The external intercostals help lift the ribs during inhalation, and the internal intercostals contract to, force dead air out of the lungs especially during strenuous exercise, when the body needs more oxygen. interstitium: The fluid-filled space between cells. lactic acid fermentation: A process which allows muscles to keep functioning even when oxygen is low by providing an additional source of ATP. The downside to this is sore muscles and fatigue, caused by the build-up of lactic acid. Copyright

5 larynx: Also called the voicebox, it connects the pharynx with the trachea. lower respiratory tract: The trachea, primary bronchi, and lungs; this is where air is conducted to and from the lungs. medulla oblongata: A portion of the brain stem, it controls respiration through inspiratory and expiratory neurons. nasal cavity: The part of the upper respiratory tract where air is warmed and humidified before traveling to the lungs. It is lined with a mucus membrane and cilia. peripheral chemoreceptors: Specialized nerve cells located in the carotid arteries and aorta that monitor blood oxygen levels. If levels drop, these stimulate the inspiratory neurons to increase depth of breathing and breathing rate. pharynx: Part of the throat leading from the mouth and nasal passages to the larynx and esophagus. pleura: A membrane surrounding the lungs. Its inner layer (the visceral pleural membrane) touches the outer surface of the lung. Its outer layer (the outer parietal pleural membrane) lines the inner wall of the thoracic cavity. These layers secrete a lubricating fluid into the pleural cavity that reduces friction during breathing. pleural cavity: The thin space between the inner and outer membranes of the pleura. primary bronchi (left and right): Bronchial tubes that connect the trachea to the lungs, forming an upside-down Y. The right primary bronchus splits into three secondary branches in the three lobes of the right lung, and the left splits into the two lobes of the left lung. pulmonary capillaries: Blood vessels covering each alveolar sac that pick up oxygen and deliver carbon dioxide to the alveoli. respiration: A process the involves the exchange of gases between the air around us and the cells of our bodies. sinuses: Also called sinus cavities, these are air-filled chambers surrounding the nasal cavity. They produce mucus, which drains into the nasal cavity. surfactant: A type of molecule secreted by Type II alveolar cells. Surfactants coat the alveoli and act to reduce their surface tension, thus preventing them from collapsing. Copyright

6 tidal volume: The volume of air inhaled and exhaled in each breath during regular breathing. trachea: Also called the windpipe, it is the part of the lower respiratory tract that connects the larynx to the bronchi, bringing air to the lungs. upper respiratory tract: The nasal passages, nostrils, sinuses, pharynx, and larynx; this is where air enters and leaves the body. Student Projects Demonstrate your understanding of the parts and functioning of the respiratory system by tracing air s journey from the nasal cavity all the way to the alveoli. Your presentation can be in the form of a written report, spreadsheet, series of labeled drawings, poster, 3-D model, video, or even a song, poem, play, or imaginative story. Make a detailed diagram to illustrate gas exchange and diffusion. For extra credit, include the role of plants in human respiration. Hay fever, sinus infection, the common cold what s going on in the upper respiratory tract when these occur? How can cold medications and home remedies provide relief? Present your findings in a brief paper. Using the library and the Internet, learn more about ATP and how it works. Then, study ads for ATP supplements targeted at bodybuilders. Do you think these supplements work? Does the reasoning presented in some of the ads hold up to scientific scrutiny? Present your findings in a brief paper. Create a mini graphic novel illustrating what happens in the respiratory system when a dancer, athlete, singer, or mountain climber exert themselves beyond their usual capacity. Investigate different types of yoga breathing, or pranayama. Then write about one type in detail, describing how air is inhaled, held, and released. Do you think the increased intake of oxygen could have a physiological effect on the body? Include in your report any legitimate scientific findings on the use of yoga breathing in stress reduction. Copyright

7 Quiz 1. The main function of the respiratory system is to provide oxygen to the cells and to dispose of. a) excess ATP b) hemoglobin c) carbon dioxide d) carbon monoxide 2. is the process whereby nutrients in food molecules are broken down to produce ATP. Oxygen must be present for this to occur. a) Diffusion b) Cellular respiration c) Lactic acid fermentation d) Oxygenation 3. True or False? The right lung has three lobes, while the left lung has only two lobes to allow room for the heart. 4. The connects to the larynx, which connects to the trachea, which connects to the. a) pharynx; bronchi b) pharynx; alveolar ducts c) bronchus; bronchi d) epiglottis; pharynx 5. Strenuous exercise can cause. a) muscle soreness due to lactic acid fermentation b) activation of intercostal muscles to force dead air out of the lungs and allow more fresh air in c) firing of expiratory neurons to signal deeper exhalation d) all of the above Copyright

8 6. After mucus has trapped tiny particles in the nasal cavity with inhalation, move(s) the particle-laden mucus toward the throat to be swallowed. a) cilia b) lubricating fluid c) oxygen d) bulk transport 7. The alveoli are the site of, the transfer of oxygen and carbon dioxide between the air and the blood. a) ATP conversion b) gas exchange c) equalization d) bulk flow 8. The two pleural membranes secrete into the pleural cavity to help reduce friction during breathing. a) oxygen b) mucus c) lubricating fluid d) carbon dioxide 9. Diffusion of oxygen in the lungs is always from the to the pulmonary capillaries. a) bronchial tubes b) alveoli c) pleural cavity d) heart 10. A person with emphysema will have a harder time breathing because the damaged lung tissue has less surface area for gas exchange to occur. This is an illustration of. a) hypoxia b) neuron impairment c) Moore s Law d) Fick s Law Copyright

9 11. True or False? By pulling the rib cage upward and outward, intercostal muscles increase lung volume, which increases pressure in the lungs. This allows air to flow in to the lungs. 12. The production of surfactants on the inner surface of the alveoli. a) helps keep the lungs inflated b) reduces friction to aid in breathing c) inhibits diffusion d) contributes to mucus in the bronchial tubes 13. When inspiratory neurons fire, they stimulate the diaphragm and external intercostal muscles to contract, causing us to. a) exhale b) inhale c) hiccup d) feel dizzy 14. monitor the rates of oxygen and carbon dioxide in the blood. If oxygen drops or CO 2 rises, these specialized cells signal neurons in the brain stem to increase the rate of breathing. a) Expiratory neurons b) Type II alveolar cells c) Pulmonary capillaries d) Chemoreceptors 15. Mountain climbers are at risk for altitude sickness because lowers oxygen levels in the blood. a) increased oxygen pressure b) strenuous exercise c) reduced oxygen pressure d) lactic acid fermentation Copyright

10 Answers to Quiz 1. c) carbon dioxide 2. b) Cellular respiration 3. True 4. a) pharynx; bronchi 5. d) all of the above 6. a) cilia 7. b) gas exchange 8. c) lubricating fluid 9. b) alveoli 10. d) Fick s Law 11. False (pressure in the lung is decreased). 12. a) helps keep the lungs inflated 13. b) inhale 14. d) Chemoreceptors 15. c) reduced oxygen pressure Please send comments, questions, and suggestions to custserv@films.com Copyright