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Unit two class review

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Terms in this set (20)

  • What causes air to move out of the lungs?
    Air moves out when the pressure inside the lungs is greater than the pressure in the atmosphere.
  • What characterizes normal quiet expiration?
    It is a passive process depending on the recoil of elastic fibers stretched during inspiration.
  • Define intrapulmonary pressure.
    It is the pressure within the alveoli of the lungs.
  • How does surfactant prevent alveolar collapse?
    By reducing surface tension of alveolar fluid through interfering with water molecule cohesiveness.
  • What is the most powerful respiratory stimulus for breathing?
    An increase of carbon dioxide in the blood.
  • What is pulmonary ventilation?
    The movement of air into and out of the lungs.
  • What is tidal volume?
    The amount of air exchanged during normal breathing.
  • What determines the direction of respiratory gas movement?
    The partial pressure gradient of the gases.
  • Name a possible cause of hypoxia.
    Too little oxygen in the atmosphere is a cause of hypoxia.
  • What lung volume represents total exchangeable air?
    The vital capacity.
  • Where are respiratory control centers located?
    In the medulla and pons of the brainstem.
  • What does the upper respiratory tract include?
    It extends from the nose through the pharynx.
  • How does the left lung differ from the right lung?
    The left lung has a cardiac notch and two lobes.
  • What is NOT a role of the pleurae?
    They do NOT assist in blood flow to and from the heart.
  • Why does breathing into a paper bag help during hyperventilation?
    It helps retain carbon dioxide in the blood.
  • What is NOT a function of the nose?
    The nose is NOT the direct initiator of the cough reflex.
  • Which factor does NOT promote oxygen binding to hemoglobin?
    The number of red blood cells does not directly affect oxygen binding.
  • What holds the lungs to the thorax wall?
    Surface tension from pleural fluid and negative pressure in the pleural cavity.
  • How do chemoreceptors regulate breathing in response to CO2?
    Increased CO2 stimulates chemoreceptors in the aorta and carotid, sending impulses to the medulla oblongata to increase heart and breathing rate.
  • What happens after breathing muscles contract faster due to increased CO2?
    More CO2 is exhaled, blood pH increases, and the system returns to normal.