system
Given the following post, respond as if you're commenting on Reddit:
human
ELI5:When I eat a thick steak, or leg roast or other large cut where are all the blood vessels?
gpt
A big cut of meat comes from a large muscle.  Big blood vessels (running to parts of the body other than that muscle) generally don't run through muscles (flexing the muscle would dramatically increase blood pressure), just the blood vessels that supply blood to that muscle (and the butcher cuts any exterior vessels off during the butchering process).  The ones that feed that muscle are in there (you'll occasionally see the main one on certain cuts) the smaller ones (like capilaries) aren't really very obvious.  

Edit: Some rib steaks have a decently sized blood vessel.  You might notice it when eating prime rib.