37-3 The Respiratory System Copyright Pearson Prentice Hall

Copyright Pearson Prentice Hall Interesting Facts The surface area of the lungs is about the same size as a tennis court You lose about ½ L of water a day through breathing Tuberculosis (TB) is caused by bacteria that destroy the air sacs in the lungs 2 million people die of TB each year Copyright Pearson Prentice Hall

Copyright Pearson Prentice Hall Lizards can’t breathe when they are running . . . their breathing depends on the muscles between their ribs which MUST be used during running The vapour that comes out of your mouth when you cough travels at about 160 km/h Some animals (some frogs) can breathe through their skin Copyright Pearson Prentice Hall

Copyright Pearson Prentice Hall One acre of trees produces enough oxygen to keep 18 people alive for one year Cigarettes and cigarette smoke contain over 4000 chemicals, including 43 known to cause cancer Every cigarette shortens your life by ~14 minutes Copyright Pearson Prentice Hall

Copyright Pearson Prentice Hall What Is Respiration? What Is Respiration? In biology, respiration means two different things. Cellular respiration is the release of energy from the breakdown of food in the presence of oxygen. At the organism level, respiration is the process of gas exchange—the release of carbon dioxide and the uptake of oxygen between the lungs and the environment. Copyright Pearson Prentice Hall

Copyright Pearson Prentice Hall Importance of Gas Exchange Composition of Atmosphere  78% Nitrogen  21% Oxygen  0.03% Carbon Dioxide   Cells obtain energy by breaking down sugars. O2 is the required. Humans need oxygen to survive (250 mL/min) Humans may live several days without water, weeks without food, only minutes without oxygen. Copyright Pearson Prentice Hall

The Human Respiratory System What is the function of the respiratory system? Copyright Pearson Prentice Hall

The Human Respiratory System The basic function of the human respiratory system is the exchange of oxygen and carbon dioxide between the blood, the air, and tissues. Copyright Pearson Prentice Hall

The Human Respiratory System The respiratory system consists of the: nose pharynx larynx trachea bronchi lungs Copyright Pearson Prentice Hall

The Human Respiratory System Air entering the respiratory system must be warmed, moistened, and filtered. Mucus moistens air and traps particles of dust or smoke. Cilia sweep particles and mucus to the throat. Mucus and particles are either swallowed or spit out. Copyright Pearson Prentice Hall

The Human Respiratory System Pharynx Nose Larynx Trachea Mouth Lungs Epiglottis Bronchus Bronchioles The respiratory system is responsible for the exchange of oxygen and carbon dioxide. Air moves through the nose, pharynx, larynx, trachea, and lungs. After reaching the lungs, the trachea branches into smaller and smaller tubes called bronchioles, which end in alveoli, or air sacs. Diaphragm Copyright Pearson Prentice Hall

The Human Respiratory System Pharynx Nose Air enters the nose or mouth and moves to the pharynx, or throat. The pharynx serves as a passageway for both air and food. The respiratory system is responsible for the exchange of oxygen and carbon dioxide. Copyright Pearson Prentice Hall

The Human Respiratory System Air moves from the pharynx into the trachea, or windpipe. The epiglottis covers the entrance to the trachea when you swallow. Trachea Epiglottis The respiratory system is responsible for the exchange of oxygen and carbon dioxide. Copyright Pearson Prentice Hall

The Human Respiratory System Larynx   At the top of the trachea is the larynx, which contains two elastic folds of tissue called vocal cords. The respiratory system is responsible for the exchange of oxygen and carbon dioxide. Air moves through the nose, pharynx, larynx, trachea, and lungs. Copyright Pearson Prentice Hall

The Human Respiratory System Air then passes through the trachea into two large passageways in the chest cavity called bronchi. Each bronchus leads into one of the lungs. Lungs Bronchus The respiratory system is responsible for the exchange of oxygen and carbon dioxide. Air moves through the nose, pharynx, larynx, trachea, and lungs. After reaching the lungs, the trachea branches into smaller and smaller tubes called bronchioles, which end in alveoli, or air sacs. Copyright Pearson Prentice Hall

The Human Respiratory System In each lung, the bronchus subdivides into smaller bronchi, and then into bronchioles. Bronchioles The respiratory system is responsible for the exchange of oxygen and carbon dioxide. After reaching the lungs, the trachea branches into smaller and smaller tubes called bronchioles, which end in alveoli, or air sacs. Copyright Pearson Prentice Hall

The Human Respiratory System Bronchioles subdivide into millions of tiny air sacs called alveoli. Alveoli Bronchiole The respiratory system is responsible for the exchange of oxygen and carbon dioxide. After reaching the lungs, the trachea branches into smaller and smaller tubes called bronchioles, which end in alveoli, or air sacs. Copyright Pearson Prentice Hall

The Human Respiratory System Alveoli are grouped in clusters. A network of capillaries surrounds each alveolus. Pulmonary artery Pulmonary vein The respiratory system is responsible for the exchange of oxygen and carbon dioxide. Capillaries Copyright Pearson Prentice Hall

Copyright Pearson Prentice Hall Gas Exchange Gas Exchange Gas exchange takes place in the alveoli. Oxygen diffuses into the blood. O2 Gas exchange occurs by diffusion across the membrane of an alveolus and a capillary. Capillary Copyright Pearson Prentice Hall

Copyright Pearson Prentice Hall Gas Exchange Carbon dioxide in the blood diffuses into the alveolus. O2 CO2 Gas Exchange Animation Gas exchange occurs by diffusion across the membrane of an alveolus and a capillary.  Capillary Copyright Pearson Prentice Hall

Copyright Pearson Prentice Hall Breathing Breathing Breathing is the movement of air into and out of the lungs. The force that drives air into the lungs comes from air pressure. Copyright Pearson Prentice Hall

Copyright Pearson Prentice Hall Breathing Lungs are sealed in pleural membranes inside the chest cavity. At the bottom of the cavity is a large, flat muscle known as the diaphragm. During inhalation the rib cage rises and the diaphragm contracts, increasing the size of the chest cavity. Copyright Pearson Prentice Hall

Copyright Pearson Prentice Hall Breathing During inhalation, the diaphragm contracts and the rib cage rises up. This expands the volume of the chest cavity. During inhalation the rib cage rises and the diaphragm contracts, increasing the size of the chest cavity. Copyright Pearson Prentice Hall

Copyright Pearson Prentice Hall Breathing The chest cavity is sealed, so this creates a partial vacuum inside the cavity. Atmospheric pressure fills the lungs as air rushes into the breathing passages. Copyright Pearson Prentice Hall

Copyright Pearson Prentice Hall Breathing Often exhaling is a passive event. When the rib cage lowers and the diaphragm relaxes, pressure in the chest cavity is greater than atmospheric pressure. Air is pushed out of the lungs. Air Exhaled Rib cage lowers During inhalation the rib cage rises and the diaphragm contracts, increasing the size of the chest cavity. Exhalation Copyright Pearson Prentice Hall

How Breathing Is Controlled Breathing is controlled by the medulla oblongata. The medulla oblongata monitors carbon dioxide in the blood. As carbon dioxide increases, nerve impulses make the diaphragm contract, bringing air into the lungs. The higher the carbon dioxide level, the stronger the impulses. Copyright Pearson Prentice Hall

Copyright Pearson Prentice Hall Measurement of Lung Function Tidal volume: volume of air inhaled and exhaled in a single breath Residual Volume: the air that remains in the airways and does not participate in gas exchange Vital capacity: the maximal volume that can be exhaled after maximal inhalation Inspiratory reserve volume: the amount of air that can be inhaled beyond the tidal volume Expiratory reserve volume: the amount of air that can be forcibly exhaled beyond the tidal volume Residual volume: the amount of air remaining in the lungs, even after a forceful maximal expiration Copyright Pearson Prentice Hall

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Tobacco and the Respiratory System Tobacco smoke contains three dangerous substances that affect the body: nicotine carbon monoxide tar Copyright Pearson Prentice Hall

Tobacco and the Respiratory System Effects on Respiratory System Nicotine is a stimulant that increases heart rate and blood pressure. Carbon monoxide is a poisonous gas that blocks the transport of oxygen by hemoglobin in the blood. Nicotine and carbon monoxide paralyze the cilia. Tar contains compounds that are known to cause cancer. Copyright Pearson Prentice Hall

Tobacco and the Respiratory System Diseases Caused by Smoking How does smoking affect the respiratory system? Copyright Pearson Prentice Hall

Tobacco and the Respiratory System Smoking reduces life expectancy. Smoking can cause such respiratory diseases as chronic bronchitis, emphysema, and lung cancer. Copyright Pearson Prentice Hall

Tobacco and the Respiratory System In chronic bronchitis, the bronchi become swollen and clogged with mucus. Emphysema is the loss of elasticity in lung tissues. People with emphysema cannot get enough oxygen to the body tissues or rid the body of excess carbon dioxide. Copyright Pearson Prentice Hall

Tobacco and the Respiratory System Smoking is a preventable cause of lung cancer. Lung cancer is deadly because its cells can spread to other locations. Smoking is also a major cause of heart disease. Copyright Pearson Prentice Hall

Tobacco and the Respiratory System Smoking and the Nonsmoker Passive smoking is damaging to young children because their lungs are still developing. Studies show that children of smokers are twice as likely as children of nonsmokers to develop respiratory problems. Copyright Pearson Prentice Hall

Tobacco and the Respiratory System Dealing With Tobacco  The best way to avoid tobacco-related illness is not to smoke. If a smoker quits, his or her health can be improved, and some of the damage can be reversed. Copyright Pearson Prentice Hall

Copyright Pearson Prentice Hall 37-3 Copyright Pearson Prentice Hall

Copyright Pearson Prentice Hall 37-3 Air passes through the trachea into two large passageways in the chest cavity known as the bronchi. alveoli. epiglottis. bronchioles. Copyright Pearson Prentice Hall

Copyright Pearson Prentice Hall 37-3 The function of the cilia lining the respiratory surfaces is to improve the amount of oxygen and carbon dioxide exchanged in the lungs. cover the opening of the trachea when you swallow. move air in and out of the lungs. sweep trapped particles and mucus away from the lungs. Copyright Pearson Prentice Hall

Copyright Pearson Prentice Hall 37-3 Oxygen diffuses from the alveolus into the blood because blood entering the capillaries of the lungs is oxygen-poor. blood entering the capillaries of the lungs is oxygen-rich. air entering the lungs has more carbon dioxide than oxygen. air entering the lungs has less oxygen than is found in the blood. Copyright Pearson Prentice Hall

Copyright Pearson Prentice Hall 37-3 A stimulant drug found in tobacco that increases the heart rate and blood pressure is tar. carbon monoxide. nicotine. carbon dioxide. Copyright Pearson Prentice Hall

Copyright Pearson Prentice Hall 37-3 A respiratory disease that results in the loss of elasticity in the tissues of the lung is chronic bronchitis. lung cancer. emphysema. pneumonia. Copyright Pearson Prentice Hall

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