Why do Miners call their mineral finds VEINS ?

Vein is a term used in geology to line lanes or "beds", are filled by mineralized fluid magma that fills the cavity in the layers of the Earth crust.

Called vein because of its shape like a branched vascular

supposed to be the most appropriate term is artery : makes the blood flows from the heart spread throughout the body = > source comes from the magma spreads in all directions which have a weak line lanes.

I don't know. But my theory is that when you look at your own body, the veins are more noticeable than the arteries due to their color. So that's what came to the mind of the miners first.