Final answer:
The bicarbonate buffer system in the bloodstream responds to a rise in [H3O+] by adjusting the pH to maintain homeostasis.
Step-by-step explanation:
The bicarbonate buffer system in the bloodstream responds to a rise in [H3O+] by adjusting the pH to maintain homeostasis. When there is an increase in [H3O+], the system works to neutralize the excess acidity. The weak acid, carbonic acid (H2CO3), reacts with the excess H3O+ to form bicarbonate ions (HCO3-) and water. This reaction helps to maintain the pH balance in the bloodstream.