Answer:
The basic function of the blood vessels is to transport the oxygen to all the tissues around the human body.
Explanation:
They carry oxygen, nutrients, and blood cells throughout the body to support the tissues, they also take from them the waste products made by them, like carbon dioxide.
Blood vessels are key to life because they provide energy to all the organs and tissues in the body and they also allow the waste products to be eliminated carrying them to the organs who perform that task.
I hope this answer helps you.
