Which one of the following is synthesised in the human body that dilates blood vessels and increases blood flow?
✓ Correct answer: a) Nitric oxide
ExplanationNitric oxide is a naturally synthesized molecule in the human body that plays a crucial role in vasodilation, which is the widening of blood vessels.It is produced by endothelial cells lining the blood vessels through the action of the enzyme nitric oxide synthase (NOS) on L-arginine.Nitric oxide diffuses into the smooth muscle cells of blood vessels.It activates an enzyme called guanylate cyclase, which increases the production of cyclic guanosine monophosphate (cGMP). cGMP causes the relaxation of smooth muscles, leading to the widening of blood vessels (vasodilation).By relaxing the smooth muscles of blood vessels, nitric oxide increases blood flow and helps regulate blood pressure.It also has important functions in immune response and neurotransmission.3
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