how is blood produced?
 

I must have been asleep during biology class because I don't recall ever learning this. The circulatory system seems like a closed loop. How does new blood get in? You hear about people bleeding to death but I've never heard that a person lost his/her ability to produce blood. There are blood quality and flow disorders. Are there blood volume disorders?

Thanks,
Sixto
95 S420
87 300SDL

It's made in your bones....that's about as far as my Biology knowledge can take me.

Botnst will know.

PX

Get a bag of turnips, then you cut one open...all will be revealed.

Apparently some elected officials believe that it can be gotten out of stones . . . ;)

How Blood Cells Are Made
All blood cells are produced in the bone marrow. As children, most of our bones produce blood. As we age this gradually diminishes to just the bones of the spine (vertebrae), breastbone (sternum), ribs, pelvis and small parts of the upper arm and leg. Bone marrow that actively produces blood cells is called red marrow, and bone marrow that no longer produces blood cells is called yellow marrow. The process by which the body produces blood is called hematopoiesis.

All blood cells (RBCs, WBCs and platelets) come from the same type of cell, called the pluripotential hematopoietic stem cell. This group of cells has the potential to form any of the different types of blood cells and also to reproduce itself. This cell then forms committed stem cells that will form specific types of blood cells.

During formation, the RBC eventually loses its nucleus and leaves the bone marrow as a reticulocyte. At this point, the reticulocyte contains some remnants of organelles. Eventually these organelles leave the cell and a mature erythrocyte is formed. RBCs last an average of 120 days in the bloodstream. When RBCs age, they are removed by macrophages in the liver and spleen.

http://health.howstuffworks.com/blood1.htm :D

I'm guessing any number of the processes described above could go wrong and cause serious uuuuuuhhh...death.

My mother told me never eat yellow snow. :P

The otehr way that I'd like to see is reverse osmosis on a vampire. You know, put pressure on his body til his fangs ooze blood. Should work, once you find a vampire.

Seems like it would be quite a good transfusion system. Hit a vein and start the squeezin'

PX