The Human Respiratory System

Jul 11, 2024

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The Human Respiratory System

Introduction

  • Function: Exchange of gases (oxygen in, carbon dioxide out)
  • Importance: Supports cellular respiration (ATP production)

Pathway of Air

  1. Nasal Cavity:
    • Air is warmed, humidified, and filtered
    • Contains mucus, nasal hairs, and microscopic cilia
  2. Pharynx
    • Junction for food and air
  3. Larynx
    • Known as the voice box
  4. Trachea
    • Cylinder tube with rings of cartilage for support
  5. Primary Bronchi
    • Two branches leading to each lung
  6. Lungs
    • Right lung: 3 lobes, Left lung: 2 lobes (includes cardiac notch for the heart)
  7. Branching within Lungs
    • Primary -> Secondary -> Tertiary Bronchi -> Bronchioles
    • Ends with alveolar ducts surrounded by alveolar sacs (resembles grapes)

Gas Exchange

  • Location: Alveoli
    • Thin-walled cells
    • Large surface area
    • In close contact with capillaries
  • Process:
    • Oxygen picked up by red blood cells
    • Carbon dioxide brought for exhalation

Interaction with Other Systems

  1. Circulatory System
    • Blood circulates oxygen and removes CO2
  2. Skeletal System
    • Ribs protect the lungs
  3. Muscular System
    • Muscles involved: Intercostal muscles, diaphragm, and abdominal muscles
  4. Nervous System
    • Regulates involuntary breathing based on blood pH

pH Regulation

  • pH Scale: Based on hydrogen ion concentration (H+)
    • Acidic: High H+ concentration (lower pH)
    • Basic: Low H+ concentration (higher pH)
  • Mechanism: Increase in CO2 increases H+ concentration -> blood becomes more acidic -> brain increases breathing rate to stabilize pH (~7.4)

Respiratory Systems in Other Species

  • Earthworms: Gas exchange through skin
  • Fish: Use gills
  • Insects: Tracheal system with spiracles

Clinical Applications

  • Careers: Pulmonologists and respiratory therapists
  • Conditions: Asthma, emphysema, respiratory distress syndrome (RDS) in premature babies
  • Treatment:
    • Importance of surfactant in alveoli
    • Artificial surfactants for premature babies to prevent alveolar collapse

Conclusion

  • Fascinating and complex interplay of systems
  • Emphasizes the importance of homeostasis and medical advancements
  • Encourage continuous curiosity in biological sciences