I keep reading, as a science student, that when blood flow or pressure goes down, arterioles constrict in order to raise blood pressure. But vasoconstriction actually increases resistance, thereby depriving the tissue further of blood flow.
So what is it that I’m not understanding?
In: Biology
The circulatory system comprises of various types of vessels with varying sized and functions. Arterioles are a type of vessel that are at the end of the arterial system but before capillaries that’s perfume into tissues. The arterioles contain the valves that do much of the constricting to create a backup in pressure from the heart pumping thus increasing pressure. While increasing resistance may up front sound like it would impede blood from reaching the tissue reframe the perspective as it’s constricting to maintain a balanced blood pressure that is neither too low nor too high. It’s goal is to not completely block flow by constricting. In a healthy individual with properly functioning systems this resistance doesn’t increase to a point that blocks off tissues or capillaries. The diameter of the vessels simply adjust to create a radius that produces adequate flow. Poiseuille’s law can be applied to this situation where radius and pressure are related. If the pressure is low the radius can be decreased to increase pressure and visa versa.
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