respiratory

• What is the primary function of the respiratory system?


  Gas exchange (O₂ uptake, CO₂ expulsion)
• What are the additional functions of the respiratory system?

  • Regulation of blood pH
  • Voice production
  • Olfaction
  • Protection against pathogens and particulate matter
• What does the respiratory system regulate to maintain acid-base balance?


  Blood CO₂ levels
• How do vocal cords contribute to voice production?


  They vibrate to produce sound.
• Where is the olfactory epithelium located?


  In the nasal cavity
• What role does the respiratory system play in protection?


  It defends against pathogens and particulate matter.
• What are the structural divisions of the respiratory system?


  • Upper Respiratory Tract: Nose to Larynx
  • Lower Respiratory Tract: Trachea to alveoli
• What are the functional divisions of the respiratory system?

  • Conducting Zone: Filters, warms, and moistens air; conducts air to the lungs
  • Respiratory Zone: Gas exchange
• What is the function of the nose and nasal cavity?

  Filters, warms, and humidifies inhaled air.
• What is the role of the pharynx in the respiratory system?


  It is a passageway for air to the larynx.
• What does the larynx contain?


  The vocal cords.
• What is the function of the trachea?


  Conducts air from the larynx to the bronchi.
• What are the types of bronchi in the respiratory system?


  • Right and left main bronchi
  • Secondary (lobar) bronchi
  • Tertiary (segmental) bronchi
• What are bronchioles?


  Small airways branching from tertiary bronchi.
• What are the two types of bronchioles?


  Terminal bronchioles and respiratory bronchioles.
• What are the lungs composed of?

  Lobes that contain alveoli.
• What is the function of alveoli?


  Exchange oxygen and carbon dioxide between air and blood.
• What are the components of the capillary-alveolar membrane?


  1. Alveolar Epithelium

  • Type I Pneumocytes: Thin, flat cells
  • Type II Pneumocytes: Secrete surfactant

  1. Basement Membrane: Thin layer supporting the alveolar epithelium
  2. Capillary Endothelium: Lining of capillaries allowing gas exchange
• What is pulmonary ventilation?


  Air movement into and out of the lungs.
• What occurs during external (pulmonary) respiration?


  Gas exchange between alveoli and blood.
• What is respiratory gas transport?


  Transport of O₂ and CO₂ in the blood.
• What is internal (tissue) respiration?


  Gas exchange between blood and tissues.
• What drives airflow in the respiratory system?

  Pressure differences between the atmosphere and alveoli.
• What happens during inhalation?

  Air flows from higher atmospheric pressure to lower alveolar pressure.
• What happens during exhalation?

  Air flows from higher alveolar pressure to lower atmospheric pressure.
• What does Boyle's Law state?


  Pressure is inversely proportional to volume within a container.
• What is the main muscle for inspiration?

  The diaphragm.
• How does the diaphragm contribute to breathing?


  It contracts and flattens to increase thoracic cavity volume.
• What percentage of air intake during quiet breathing is due to the diaphragm?


  ~75%
• What do external intercostal muscles do during inhalation?


  Lift ribs upward and outward to expand thoracic cavity.
• What percentage of air intake during quiet breathing is due to external intercostal muscles?


  ~25%
• What are the accessory muscles of inhalation?


  • Scalenes: Elevate the first two ribs
  • Sternocleidomastoid: Elevates the sternum
  • Pectoralis Minor: Lifts the ribs and sternum
• What happens to the diaphragm during exhalation?


  It relaxes, moving back to its dome-shaped position.
• What do external intercostal muscles do during exhalation?


  Relax, allowing ribs to move downward and inward.
• What do internal intercostal muscles do during active or forced exhalation?


  Contract to pull ribs downward and inward.
• How do abdominal muscles assist in forced exhalation?


  They contract to push the diaphragm upward.
• What are the types of respiratory pressures?

  • Barometric Air Pressure (PB)
  • Intra-alveolar Pressure (Palv)
  • Pleural Pressure
• What is the typical barometric air pressure at sea level?


  760 mm Hg
• What is the intra-alveolar pressure at rest?


  Equals barometric pressure (PB); no air movement.
• What happens to intra-alveolar pressure during inhalation?


  It drops to approximately -1 mm Hg.