Neurovascular coupling is optimized to compensate for the increase in proton production from nonoxidative glycolysis and glycogenolysis during brain activation and maintain homeostasis of pH, pCO2, and pO2

The human body keeps the pH of its blood and fluids between 7.35 and 7.45 using chemical buffers and regulatory processes.

During brain activity, oxygen extraction from blood stays around 42% even when the brain needs more energy, because the design of brain capillaries prevents oxygen levels from rising too high despite increased blood flow.

When the brain becomes more active, oxygen levels in brain tissue stay stable because the capillaries adjust how much oxygen they release, preventing both too little and too much oxygen in the tissue.

When the brain becomes active, blood flow increases much more than oxygen use to keep chemical levels stable, removing acid byproducts produced by energy processes that do not require oxygen.

When the brain becomes active, it produces energy through a process that generates protons at three times the rate of its oxygen-based energy production, and this excess of protons requires increased blood flow to keep the brain's acidity stable.

In the brain, the coordination between blood flow and oxygen delivery to neurons must remain precise; even minor reductions in capillary density or blood flow disrupt the balance of pH and gases, impairing normal function.