1. Physical Exercise
   • Increases respiration rate
   • More CO2 produced
   • Higher demand for O2
2. Excitement and Sudden Fear
   • Adrenaline release
   • Increases breathing rate
3. Elevated CO2 Levels in Blood
   • Stimulates the medulla oblongata
   • Increases respiration rate
4. Lower CO2 Levels in Blood
   • Reduces breathing rate as more O2 reaches cells

Effects of Exercise on Breathing:

• Breathing involves air intake and expulsion from the lungs.
• Influenced by temperature, health, exercise, emotions, and age.
• Exercise increases muscle energy demands, requiring more O2 and glucose (C6H12O6).
  
• CO2 is produced as a byproduct