試題詳解

54.Imagine that a mutant mouse has a defect in the distribution of norepinephrine receptors, so that all the arteries and arterioles carry the type of norepinephrine receptor normally found around the brain and heart. What would you predict for this mouse in response to hemorrhage?
(A) Vessels throughout the body will stay dilated, resulting in inadequate blood flow to the brain and heart.
(B) Vasoconstriction near the brain and heart will prevent enough blood from reaching those organs.
(C) Blood vessels near the brain and heart will be dilated, while blood vessels elsewhere will constrict.
(D) Blood vessels near the brain and heart will constrict, while blood vessels elsewhere will be dilated.