Control of Blood pH

• 1 - CO2 increases, so lower pH

  (dissociates more into more weak carbonic acid)
• 2 - chemoreceptor detects changes
• 3 - sensory information passed to cardiovascular centre
• 4 - sympathetic nerve passes excitatory impulses to SAN
• 5 - heart rate increases, so more blood flow to lungs
• 6 - CO2 reaches lungs to be diffused and exhaled
• 7 - CO2 levels decrease, so excitation of SAN decreases
• 8 - parasympathetic system begins to counteract increase in heart rate, allowing heart rate to return to normal