Do humans have the same blood that we had as a kid? How come blood doesn’t expire inside of us since we range from different temperatures and are exposed to oxygen etc.

Question

Do we somehow maintain the same blood for the rest of our lives and we just pump more if we lose some. Blood expires in hospitals and not when inside of us?

In: Biology

Answer 1

Your blood, along with almost every other cell in your body, is being constantly renewed. With red blood cells it is the job of the liver to cull old red blood cells and this is the primary reason why your poo is brown – oxidised iron in old red blood cells being excreted.

The average lifespan of a red blood cell is 120 days. Most other cells in your body have an expiry date.