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17.2: Respiratory System Anatomy

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    125472
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    The trachea is a long tube supported by cartilage rings to keep it open. It is continuous with the larynx and ends before it splits into the primary bronchi in the chest. The tracheal wall is composed of layers of connective tissue and epithelial tissue. As the air travels down the trachea -> the bronchial tree -> the bronchi -> the bronchioles -> the terminal bronchioles -> the respiratory bronchioles -> the alveolar duct -> air then arrives at the alveoli. Gas exchange takes place across the alveolar wall and capillary wall. Carbon dioxide leaves the blood vessels into the lungs, and oxygen leaves the lungs into the blood vessels.

    Diagram of the respiratory system with the trachea, bronchi, and lungs, alongside a histology slide of lung tissue.
    Figure \(\PageIndex{1}\) Trachea: (a) The tracheal tube is formed by stacked, C-shaped pieces of hyaline cartilage. (b) The layer visible in this cross-section of tracheal wall tissue between the hyaline cartilage and the lumen of the trachea is the mucosa, which is composed of pseudostratified ciliated columnar epithelium that contains goblet cells. LM × 1220 (Image and caption credit: "Trachea" by OpenStax is licensed under CC BY 4.0)
    Diagram of lung anatomy showing airways, alveoli, and associated blood vessels in red and blue.
    Figure \(\PageIndex{2}\) Respiratory Zone: Bronchioles lead to alveolar sacs in the respiratory zone, where gas exchange occurs. (Image and caption credit: "Respiratory Zone" by OpenStax is licensed under CC BY 4.0)

    Observe the following structures on the models during your instructor's demonstration.

    Upper respiratory

    1. Nasal cavity
    2. Nasopharynx
    3. Oropharynx
    4. Laryngopharynx
    5. Larynx
      • Epiglottis
      • Vocal fold
    6. Trachea

    Lower respiratory

    1. Main (Primary) bronchi
    2. Secondary bronchi
    3. Tertiary bronchi
    4. Terminal bronchial
    5. Respiratory bronchial
    6. Alveolar duct
    7. Alveolar sac
    8. Alveoli
    9. Lungs

    This page titled 17.2: Respiratory System Anatomy was last modified on Wed, 03 Dec 2025 22:52:43 GMT and is shared under a CC BY-NC-SA 4.0 license and was authored, remixed, and/or curated by Harmony Folse.