The need to provide a supply of blood is a daily effort.
You might not think about the blood that is pumping through your body at this very minute. However, when there is an accident, a surgery, a disaster or a pandemic, the need for a continuous blood supply rapidly becomes evident.
For a very short video on the blood supply in the Pacific Northwest, see this Disaster Zone TV episode: "Bloodworks NW."
My video is a bit wonky, but the message is still clear.