Gas Exchange In Humans
Aperçu
Every cell in your body is burning glucose right now, and to do it they all need a steady supply of oxygen and a way to get rid of carbon dioxide. Your lungs are the organ that makes this exchange happen, trading gases with the air millions of times a day without you ever thinking about it.
In this lesson you will see how the lungs are built for fast diffusion, trace the path air takes from your nose to the alveoli, find out exactly how breathed-in air differs from breathed-out air, and learn how your ribs and diaphragm pump air in and out. You will also discover the clever cleaning system that keeps dust and germs out of your lungs.
Objectifs
- Describe the features of gas exchange surfaces in humans, limited to: large surface area, thin surface, good blood supply and good ventilation with air
- Identify in diagrams and images the following parts of the breathing system: lungs, diaphragm, ribs, intercostal muscles, larynx, trachea, bronchi, bronchioles, alveoli and associated capillaries
- Investigate the differences in composition between inspired and expired air using limewater as a test for carbon dioxide
- Describe the differences in composition between inspired and expired air, limited to: oxygen, carbon dioxide and water vapour
- Investigate and describe the effects of physical activity on the rate and depth of breathing
- [Supplement] Identify in diagrams and images the internal and external intercostal muscles
- [Supplement] State the function of cartilage in the trachea
- [Supplement] Explain the role of the ribs, the internal and external intercostal muscles and the diaphragm in producing volume and pressure changes in the thorax leading to the ventilation of the lungs
- [Supplement] Explain the differences in composition between inspired and expired air
- [Supplement] Explain the link between physical activity and the rate and depth of breathing in terms of: an increased carbon dioxide concentration in the blood, which is detected by the brain, leading to an increased rate and greater depth of breathing
- [Supplement] Explain the role of goblet cells, mucus and ciliated cells in protecting the breathing system from pathogens and particles
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Félicitations, vous avez terminé la leçon sur Gas Exchange In Humans. Maintenant que vous avez exploré le concepts et idées clés, il est temps de mettre vos connaissances à lépreuve. Cette section propose une variété de pratiques des questions conçues pour renforcer votre compréhension et vous aider à évaluer votre compréhension de la matière.
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Utilisez cette section d'évaluation comme une occasion de renforcer votre compréhension du sujet et d'identifier les domaines où vous pourriez avoir besoin d'étudier davantage. Ne soyez pas découragé par les défis que vous rencontrez ; considérez-les plutôt comme des opportunités de croissance et d'amélioration.
- Which feature of the alveoli does NOT speed up gas exchange? A. a large surface area B. a thick muscular wall C. a thin wall D. a good blood supply Answer: B
- Compared with inspired air, expired air contains: A. more oxygen and less carbon dioxide B. less oxygen and more carbon dioxide C. more oxygen and more carbon dioxide D. less oxygen and less carbon dioxide Answer: B
- Which test shows that expired air contains more carbon dioxide? A. iodine turns blue-black B. Benedict's turns brick-red C. limewater turns milky D. biuret turns purple Answer: C
- During inspiration the diaphragm: A. relaxes and moves up B. contracts and moves down C. stays domed D. is not involved Answer: B
- The correct order of structures for air entering the lungs is: A. trachea, larynx, bronchus, alveolus B. larynx, trachea, bronchus, alveolus C. bronchus, trachea, larynx, alveolus D. alveolus, bronchus, trachea, larynx Answer: B
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Livres recommandés
Pour aller plus loin, ressources libres
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Section de manuel
Systems of Gas Exchange
Describe the passage of air from the outside environment to the lungs
"Biology: Systems of Gas Exchange" by OpenStax, OpenStax, Rice University, licensed under CC BY 4.0 (https://creativecommons.org/licenses/by/4.0/). Source: https://openstax.org/books/biology/pages/39-1-systems-of-gas-exchange. Access for free at https://openstax.org/books/biology/pages/1-introduction
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Section de manuel
Breathing
Describe how the structures of the lungs and thoracic cavity control the mechanics of breathing
"Biology: Breathing" by OpenStax, OpenStax, Rice University, licensed under CC BY 4.0 (https://creativecommons.org/licenses/by/4.0/). Source: https://openstax.org/books/biology/pages/39-3-breathing. Access for free at https://openstax.org/books/biology/pages/1-introduction
Publiées par d'autres organisations sous licence libre, créditées comme elles le demandent. Les liens ouvrent leurs sites.
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