Brain blood flow autoregulation
a. is more sensitive to ph than to a decreased oxygen level.
b. causes constriction of cerebral blood vessels in response to a drop in systemic blood pressure.
c. is controlled by cardiac centers in the pons.
d. is triggered when abnormally high co2 (carbon dioxide) levels persist.

The best response to the question: Brain blood flow autoregulation:___, would be, B: causes constriction of cerebral blood vessels in response to a drop in systemic blood pressure.

Explanation:

The maintenance of blood pressure for the brain is vital. This organ alone consumes around 20% of the total amount of oxygen available in the body, and whenever conditions change for the worse, the brain will generate actions to ensure that its blood flow is maintained. To do this, the brain has the capacity for autoregulation, meaning, the organ itself has the means to control the process, even if the rest of the body cannot. To do this, the brain resorts to several different mechanisms, and as of today, scientific research cannot assure that one mechanism is primary over others. What it is known for sure is that changes in systemic pressure drive the brain to initiate mechanisms of autoregulation to ensure that the flow, and pressure for nutrition and gas exchange in the brain, will be maintained. That is why the answer is B.