Here's a TRIPPY ANATOMY GEEK MOMENT for you: blood flows in our body through *blood vessels* (arteries, veins, capillaries, etc.), and these blood vessels form a complex network that fills our body from head to toe. The tissues of our body are nourished as the blood flows through these vessels (specifically the capillaries).
Now here's the TRIPPY PART (if that wasn't already trippy because how is our body so complex and amazing, right?) But anyway, the TRIPPY PART is that our *largest* blood vessels are so large that they need their *own* individual blood vessel system just to support them. So within the outer walls of our largest blood vessels, there lie tiny arteries, veins, and capillaries - an actual mini-blood vessel network within a larger blood vessel itself.
So the overarching blood vessel system that supports our entire body is in turn supported by a mini-version of itself. As my friend Maddy would say, that is so meta. 😜
These tiny blood vessels-within-blood vessels are called "vasa vasorum", which means - get this - "vessels of the vessels".
I hope you enjoyed your trippy anatomy geek fact of the day!