the.com/bloodstream

means The blood as it circulates through your body, carrying oxygen, nutrients, and whatever else hitched a ride, to every cell that needs them.

from A straightforward compound of 'blood' and 'stream,' built in the 19th century once physiology had a firm grip on the idea that blood flows in a continuous circuit rather than sloshing around as older medicine imagined — the word simply names what Harvey's work on circulation had already proven: blood moves like a current, so it earned a current's name.