Final answer:
The effect of input to the arterioles on blood pressure can be seen in vasoconstriction, which increases blood pressure, and vasodilation, which decreases it. These processes are regulated by the autonomic nervous system and influenced by hormones like epinephrine and angiotensin II.
Step-by-step explanation:
The impact of arteriole input on blood pressure involves mechanisms of vasoconstriction and vasodilation. When vasoconstriction occurs—narrowing of the arterioles—there is increased resistance against blood flow, which in turn increases blood pressure. This is similar to tightening the nozzle on a garden hose, causing the water to spray out with more force. Conversely, vasodilation—the widening of arterioles—results in decreased resistance and therefore lowers blood pressure, akin to loosening the nozzle. In the context of a decrease in blood pressure, the autonomic nervous system may trigger the release of epinephrine and norepinephrine, further promoting vasoconstriction to elevate pressure. Moreover, angiotensin II, a potent vasoconstrictor, helps in maintaining blood pressure, especially during blood loss or dehydration.