By sticking a needle in your vain, and using a pump to extract blood:)
Doctors don't check how much blood you have in your body. They do a best guesstimate based on size and weight. Some lab tests check the relative and absolute numbers of blood cells per unit volume.
they take blood pressures, take x-rays to doctors, give injections to people, flirt with doctors lol
Yes. If you take a drug test, doctors will know by the elements in your blood, as drugs stay in your body for some time, and that may be a long time in cases.
Filtering blood from a patients body and making sure it is clean
everywhere in your body.
they take blood to the heart or take through you're body
Take blood around your body.
yes because then you will die if no blood is pumped through your body :P
The composition of water in our blood is about 92%.
docters because they take care of the human body
The time it takes for blood to drain out of the body can vary depending on factors such as the size of the blood vessels, the amount of blood in the body, and the cause of bleeding. In general, it can take a few minutes to several hours for all the blood to completely drain out.
It takes about 1 minute for your blood to circulate throughout your body.