Blood vessels that are larger can be felt, like arteries and veins, though it is easier to feel arteries because they have a pulse.
Veins, Arteries (Capillaries are also blood vessels, but the main job is gas exchange).
your arteries, not your veins.
First it should be clear that blood can't clot only in the presence of a anticoagulant or/and in the absence of clotting factors. if anticoagulant is not there in the vicinity of blood then blood...
small blood vessels called Vaso Vasorum these are for large arteries others by diffusion