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Anatomy & Physiology: Respiratory System

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  • What are the major organs of the respiratory system?

    The major organs include the nose, pharynx, larynx, trachea, bronchi, and lungs (alveoli).

  • What is the function of the nasal conchae?

    They increase surface area, create air turbulence within the nasal cavity, and help trap inhaled particles.

  • Name the three regions of the pharynx.

    Nasopharynx (superior), oropharynx (middle), and laryngopharynx (inferior).

  • What is the role of the epiglottis in the respiratory system?

    The epiglottis is a flap of elastic cartilage that protects the larynx by routing food to the esophagus and air toward the trachea during swallowing.

  • What are the vocal folds and their function?

    Vocal folds (true vocal cords) vibrate with expelled air to produce sound for speech.

  • Describe the structure of the trachea.

    The trachea is a 4-inch tube reinforced with C-shaped hyaline cartilage rings, lined with pseudostratified ciliated columnar epithelium (PCCE) that traps debris and moves mucus upward.

  • What is the function of the pleura in the lungs?

    Pleura are membranes: the pulmonary (visceral) pleura covers lungs, and the parietal pleura lines the thoracic cavity. Pleural fluid reduces friction during breathing.

  • What structures make up the respiratory zone where gas exchange occurs?

    The respiratory zone includes respiratory bronchioles, alveolar ducts, alveolar sacs, and alveoli.

  • What is the respiratory membrane and its function?

    The respiratory membrane is formed by alveolar and capillary walls; it allows gas exchange by diffusion between air and blood.

  • What role do alveolar macrophages play?

    Alveolar macrophages (dust cells) protect lungs by engulfing bacteria, carbon particles, and debris.

  • What is surfactant and its function in the lungs?

    Surfactant is a lipid molecule secreted by alveolar cells that reduces surface tension to prevent alveolar collapse.

  • List the four events of respiration.

    1. Pulmonary ventilation (breathing)
    2. External respiration (gas exchange in lungs)
    3. Respiratory gas transport (bloodstream transport)
    4. Internal respiration (gas exchange in tissues)

  • What happens during inspiration (inhalation)?

    The diaphragm contracts downward and external intercostal muscles contract outward, increasing lung volume and decreasing alveolar pressure, causing air to flow in.

  • What happens during expiration (exhalation)?

    Diaphragm and intercostal muscles relax, lung volume decreases, alveolar pressure increases, and air flows out of the lungs.

  • How is oxygen transported in the blood?

    Most oxygen binds to hemoglobin forming oxyhemoglobin, while a small amount dissolves in plasma.

  • How is carbon dioxide transported in the blood?

    Most carbon dioxide is transported as bicarbonate ion (HCO3-) in plasma; some binds to hemoglobin at different sites forming carbaminohemoglobin.

  • What is the difference between external and internal respiration?

    External respiration is gas exchange between alveoli and pulmonary blood; internal respiration is gas exchange between blood and tissue cells.

  • Where are the neural centers controlling respiration located?

    In the medulla oblongata (ventral respiratory group) and the pons, which regulate breathing rhythm and smoothness.

  • What chemical factor most strongly influences breathing rate?

    Increased carbon dioxide (CO2) levels in blood, which lower pH, stimulate the medulla to increase breathing rate and depth.

  • What are the main features of chronic bronchitis?

    Inflammation of lower respiratory mucosa with excessive mucus production, impairing ventilation and gas exchange.

  • What characterizes emphysema?

    Destruction of alveolar walls, lung fibrosis, loss of elasticity, and difficulty exhaling, leading to overinflated lungs.

  • What are the three common types of lung cancer?

    Adenocarcinoma, squamous cell carcinoma, and small cell carcinoma, often caused by smoking.