Lesson 9

• What is the primary function of the lungs in humans?

  Gas exchange
• What is the singular form of bronchi?

  Bronchus
• What type of cells line the trachea?

  Ciliated epithelial cells and goblet cells
• What is the role of cilia in the trachea?

  They move mucus up and out
• What do goblet cells secrete?

  Mucus
• What happens to mucus after it traps dirt and pathogens?

  It is swallowed and destroyed in the stomach
• Why are alveoli highly folded?

  To increase surface area for gas diffusion
• What type of epithelium makes up the alveolus wall?

  Squamous epithelium
• How does the thickness of the alveolus wall affect gas exchange?

  It provides a short diffusion distance
• What maintains a constant diffusion gradient in the alveoli?

  A vast network of blood capillaries
• What happens to carbon dioxide during gas exchange?

  It diffuses into the alveolar air space
• How does oxygen move from the alveolus to the blood?

  It diffuses across the alveolus and capillary walls
• What role does elastin play in the lungs?

  It helps the alveoli recoil during exhalation
• What occurs during inspiration?

  Diaphragm contracts and lung volume increases
• What happens during expiration?

  Diaphragm relaxes and lung volume decreases
• What is Chronic Obstructive Pulmonary Disease (COPD)?

  A group of lung conditions causing breathing difficulties
• What is chronic bronchitis?


  Long-term inflammation of the bronchi
• How does emphysema affect the lungs?

  It damages alveoli, reducing surface area
• What is fibrosis in the lungs?

  Thickening of the epithelial tissue
• What are common symptoms of COPD?

  Decreased oxygen levels and increased breathing rate
• What can cause long-term lung damage leading to COPD?

  Inhaling harmful substances
• What is a finger pulse oximeter used for?

  Measuring blood oxygen saturation
• What is the normal blood oxygen saturation level?

  Above 95%
• How is respiratory rate measured?

  By counting chest rises and falls
• What is the normal respiratory rate at rest?

  12 breaths per minute
• What is the normal body temperature range for adults?

  36.5°C to 37.2°C
• What is tissue fluid?

  A substance bathing all body cells
• How is tissue fluid formed?

  When blood enters capillary networks
• What causes high hydrostatic pressure in capillaries?

  Reduction in diameter compared to arterioles
• What happens to fluid in the blood plasma during capillary exchange?

  Most fluid is forced out through capillary walls
• What remains in the blood plasma after fluid loss?

  Large plasma proteins and cells
• What is the role of lymphatic capillaries?

  To carry excess tissue fluid away
• What is the lymphatic system primarily responsible for?

  Removing excess fluid from tissues
• What happens to lymph as it passes through lymph nodes?

  It is filtered for bacteria and damaged cells
• What causes lymph nodes to swell?

  Increased lymphocytes and macrophages during immune response
• What are the main components of the respiratory system involved in gas exchange?

  • Lungs
  • Alveoli
  • Trachea
  • Bronchi
  • Bronchioles
• What are the symptoms of Chronic Obstructive Pulmonary Disease (COPD)?

  • Decreased oxygen levels in blood
  • Increased breathing rate
  • Shortness of breath
  • Dizziness and tiredness
  • Persistent chesty cough
  • Frequent chest infections
• What are the steps in the formation and return of tissue fluid?

  1. Blood enters capillary networks.
  2. High hydrostatic pressure forces fluid out.
  3. Fluid contains oxygen and nutrients.
  4. Some fluid returns to blood via osmotic pressure.
  5. Excess fluid drains into lymphatic capillaries.
• What are the functions of the lymphatic system?

  • Remove excess tissue fluid
  • Drain fluid back into blood circulation
  • Play a role in immune response
• What is the significance of measuring blood oxygen saturation?

  • Indicates oxygen levels in blood
  • Normal values above 95%
  • Below 90% may require medical consultation