Final answer:
Local anesthesia can cause arteries to constrict and increase cardiac output, leading to an increase in blood pressure and volume, though it is not primarily used for its effects on the cardiovascular system.
Step-by-step explanation:
The effect of local anesthesia on the cardiovascular system is not to increase the concentration of the heart, the force of contraction, or to directly relax smooth muscles of the blood vessels. Instead, one of the direct effects of local anesthesia is to cause arteries to constrict and increase cardiac output, which can result in an increase in blood pressure and volume. This vasoconstriction effect is similar to the body's natural response in situations such as significant blood loss, where sympathetic stimulation triggers the release of epinephrine and norepinephrine, enhancing both vasoconstriction and cardiac output to increase blood pressure to compensate for the loss.