Do all humans have the same number of veins and arteries? If so, how does the body know how many and where to make these veins and arteries?
In: Biology
When humans are conceived the DNA we get from our mom and the DNA we get from our dad combine to make one big blueprint of the entire human body. It’s ~99% similar for all humans. It’s why we all have a brain, liver, kidneys, etc. All the major stuff is the same in each human because of the blueprints we share in our DNA.
I think you might be thinking of *capillaries*, though? Arteries and Veins are like the highway system for blood in the human body while capillaries (small blood vessels) are like the side streets. Capillaries help deliver blood to tissues away from the “highway”. The bigger a person is (both in terms of height and body fat) the more capillaries they need.
TL;DR: We’re born with the major veins and arteries we need, but the body builds capillaries and blood vessels on demand.
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