Which one of the following is synthesised in human body that dilates blood vessels and increases blood flow…

Nitric oxide (NO) is synthesized in the human body by the enzyme nitric oxide synthase from the amino acid arginine. It plays a crucial role in dilating blood vessels, which increases blood flow and reduces blood pressure. This function helps in regulating cardiovascular health.

_Why the other options are incorrect:_

B. Nitrous oxide: Used as an anesthetic, not a vasodilator.

C. Nitrogen dioxide: A toxic air pollutant, not involved in vasodilation.

D. Nitrogen pentoxide: A reactive compound, not related to blood vessel dilation.