Question

multiple choice question
the cerebral arteries dilate when systemic bp drops and ______ when it rises, thus maintaining a relatively constant cerebral blood flow.

○ dilate

○ constrict

Explanation:

To maintain constant cerebral blood flow, when systemic blood pressure (BP) rises, cerebral arteries should constrict (opposite of dilate which happens when BP drops) to regulate flow. "Dilate" would not help regulate as it's the same as when BP drops, while "constrict" counteracts high BP to keep flow steady.

Answer:

B. constrict (assuming the options are labeled with "dilate" as one option and "constrict" as the other, with "constrict" being the correct choice)