5-6 pints to 3-4 pints, how is new blood formed?

How is new blood formed? If your asking I got this question from abook that said adults have more blood than children, and that just made no sense to me.

it takes your body a while to make new blood
but it is true that adaults have more. children are small so adaults can have more blood in the because there a lot bigger.

Your body will go into vasoconstriction. Vasoconstriction is the constrictions of blood vessels in the body to increase resistance to blood flow. This will make sure your blood pressure stays high enough to sustain normal body functions.

The body will then try to restore the loss of blood. You will get thirsty. Thirst makes you drink water to relieve the need for vasoconstriction. Then over the next few days, the bone marrows will be in a hyperactive state to make additional blood cells. Your kidneys will adjust its functions accordingly, too, to make sure when the water and the new blood cells go together the ions and proteins are balanced.

The volume of the blood and plasma be replaced relatively quickly, but the development of red blood cells will take longer.