Without blood there is no animal or human life. This reddish liquid flows through veins and arteries to oxygenate and nourish the body, like sap in a tree. Here are some statistics
 | How much blood does the body hold?
On average, adults have 5 to 6 litres: less than a bucket-full!
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| How much blood does the heart pump?
The heart pumps, on average, at a rate of 70 to 75 beats/minute.
Each minute 5 or 6 litres of blood are circulated around the body
This means that on a normal day, some 10 tonnes of blood are moved - the equivalent of 120 tankfuls of fuel in the average family car
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| How far is the blood pumped?
The combined length of arteries, arterioles, capillaries, venules and veins is around 100,000 miles (Almost 4 times round the earth!)
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| Why does the blood have to circulate?
Every minute a two-way operation occurs: - delivering oxygen and nutrients to the body's 75 trillion cells via the capillaries
- exchanging for wastes and carbon dioxide
The veins return the wastes and carbon dioxide before the blood is re-oxygenated for the next round trip
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