Blood pH must stay in a very thin band: 7.35 to 7.45. Add acid or base. Watch the bicarbonate buffer fight to hold the line.
Blood pH: 7.40
Blood pH7.35 – 7.45
Bicarbonate buffer: CO₂ + H₂O ⇌ H₂CO₃ ⇌ H⁺ + HCO₃⁻. Add acid → HCO₃⁻ mops up the H⁺. Add base → carbonic acid gives off H⁺. The equation shifts to soften the change.
📷 Reference image
A real labeled figure to compare with the interactive above.
Blood pH & Buffers — OpenStax, CC BY 3.0 (via Wikimedia Commons)
