Final answer:
In myogenic regulation of cerebral blood flow, increased levels of CO2 lead to arteriolar dilation, not increased brain pH or arteriolar constriction. This dilation increases blood flow and helps remove excess CO2.
Step-by-step explanation:
In myogenic regulation of cerebral blood flow, the response to increased levels of carbon dioxide (CO2) is not an increase in brain pH but rather a change in the diameter of arterioles. Increased CO2 levels typically lead to a decrease in blood pH due to the formation of carbonic acid, which dissociates into hydrogen ions (H+) and bicarbonate ions (HCO3−).
The response of the brain's blood vessels to increased CO2 is a myogenic response, where arterioles dilate. This dilation is a result of the smooth muscles in the walls of the arterioles relaxing in response to the higher CO2 levels, which also corresponds to increased H+ concentration. The dilation serves to increase blood flow and help remove excess CO2, thereby aiding in the restoration of the proper pH balance.
This process is crucial for maintaining consistent flow to the capillary network and ensuring the proper function of the brain's tissues. Therefore, the correct answer to the student's question is arteriolar dilation.