Where does all our blood come from?
I used to think we had a set amount of blood from birth but I know this is super not true. But I still don't know where our blood comes from?? Help
I used to think we had a set amount of blood from birth but I know this is super not true. But I still don't know where our blood comes from?? Help
Tree
If you're wondering where blood comes from originally it happens around the 13-15th day during gestation.
There are three layers to an embryo the ectoderm (the exoskeleton (e.g. skin)), mesoderm (organs), and endoderm (inner linning of organs). Blood develops within the mesoderm in what are termed blood islands.
Bulldog redux
Blood is manufactured by the body's hematopoietic cells.
The Oracle of Omigod
Blood is generated by the marrow in our bones.
Elaine M
Your blood is made in the spongy interior of the leg and arm bones, it exits through those tiny holes in it (look at a chicken leg bone next time, you'll see the holes).
Anonymous
Your body makes it. Google "blood formation"