Because this shape works for the body. Somewhere in the evolution time line the creature which had the first cylindrical blood vessel survived and that information has been stored in the DNA and has past it on to its offspring.
The reason I believe it works is that it is the easiest shape to dilate or constrict.
Tagalog of cylindrical: mabilog
Bending a rectangular sheet into a cylindrical shape.
The cylindrical barrel floated down the stream.
Yes, they're usually cylindrical in shape.
A cylindrical magnet is an artificial magnet. It is made of iron, cobalt and nickel.
10 figure we make from cylindrical shape
long, cylindrical
Maps with cylindrical projections are designed as if a cylinder has been wrapped around a globe
They are cylindrical
Volume of a cylindrical tank in cubic units: pi*radius2*height
The adjective form is cylindrical.
What is the difference between cylindrical and prismatic battery cells?