[jambutty]

Originally Posted by Neil

No blood is not sucked out of a dead body. You create a low pressure in the syringe, the body is at atmospheric pressure, so the blood moves to the low pressure in the syringe.

But it doesn’t push the syringe plunger to create the vacuum. The nurse does that by pulling the plunger.

At some time in your life, surely you must have seen a nurse take a small bottle of sterilised water, stick a hypodermic needle into it through the rubber seal, draw off some of the water and transfer it to another bottle that holds the medication that will be injected into someone. There is no air in the bottle of sterilised water so the water must be sucked out.

According to the Oxford English Dictionary:
• verb 1 draw into the mouth by contracting the lip muscles to make a partial vacuum.
2 hold (something) in the mouth and draw at it by contracting the lip and cheek muscles.
3 draw in a specified direction by creating a vacuum.

Nothing to say about:
Re your analogy of the fireman’s water pump. You can still pump water out of a sealed container where air is prevented from replacing the removed water. It takes more effort but it can still be done. Therefore the water is sucked out.

The definition of a Suction Pump
Noun - a pump for raising fluids by suction
http://uk.ask.com/reference/dictionary/wordnetuk/178384/suction%20pump

Attach a vacuum pump to a bell jar and set it going. It will be sucking the air out of the bell jar.

Basically it amounts to - when you remove air or a liquid from somewhere you suck it out. When you put air or liquid into a container of some sort you pump it in.