What Is Exhaled? Carbon Dioxide and Respiration

Exhalation: Removing Metabolic Waste

When you breathe out, you expel carbon dioxide (CO₂), the primary waste product of cellular respiration.

Process

1. Cells oxidize glucose + O₂ → ATP + CO₂ + H₂O.
2. CO₂ diffuses into blood → carried as bicarbonate (HCO₃⁻), dissolved CO₂, and carbaminohemoglobin.
3. Blood reaches pulmonary capillaries → CO₂ diffuses into alveoli.
4. Exhalation removes CO₂ from body.

Why It Matters

• CO₂ levels regulate blood pH (respiratory compensation).
• Ventilation adjusts to metabolic demand (exercise ↑ CO₂ → ↑ breathing).