and your blood travels 12,000 miles.

Egyptians believed it wasn't blood that travelled

they believed that the heart and other organs had

wills of their own and could move around

independently inside the body.

In the Fourth Century BC, Aristotle

- who by all accounts look like a cross between a hipster and Rory McGrath -

said the heart was the seat of intelligence, motion and sensation

and that it was a hot, dry organ.

Other organs, he thought, like the

brain and liver merely existed to keep the heart cool.

Around 275BC, a guy called Erasistratus almost figured

out the principle of circulation

but thought that the heart pump air containing the

animal spirits around the body.

Before you write him off as a dunce

it's worth noting that after death the

heart and arteries don't contain blood

as it pools in the veins, so this theory

held up for about 500 years until Galen

- shown here having just walked into a plate glass window -

started prodding about in hearts.

He said, [bad Greek accent] "The heart is, as it were,

the hearthstone and source of the innate heat by which the animal is governed."

I wish they weren't all Greeks

I can only really do German and French accents.

Galen felt the heart was secondary

to the liver in importance, since it didn't produce any humour.

The heart continued to be studied in Europe

and Islam, where in the 1200s, Ibn-al-Nafiz

correctly traced pulmonary circulation

but he wasn't very popular at parties and

no one paid any attention.

So it wouldn't be until 1628, when English

physicist William Harvey wrote On the Circulation of Blood,

that we would know that the heart's one role is the

transmission of the blood and its

propulsion by means of the arteries to

the extremities everywhere.

He once restarted an arrested pigeon's heart by flicking it

Very scientific, isn't it?

Flick it.

He realised that blood had to be circulated

when he calculated the volume of blood

being pumped by the heart.

The irony being that he could have learned from

any butcher that cutting an artery would

leave an animal completely exsanguinated

in a matter of minutes.

Amazingly, the effect of electricity

on the heart was being researched as

early as the 1770s. A British physician

called Squires stimulating the heart of

a young girl with electricity in 1774

and a Danish physicist called Abildgaard

reanimating a chicken after

trying electric shocks on various bits of it.

Don't play with your food.

In 1797, Alexander von Humboldt

found a dead bird in his garden

and brought it back to life

by placing electrodes in its beak

and rectum. He then tried the experiment on

himself, with less favourable results...

During the French Revolution

Bichat and Nysten used electricity to restart the hearts

of some of the many beheaded

bodies cluttering up the place.

Astonishingly, pacemakers were being

trialled as early as the late 1920s

developed independently in Australia and America.

In 1957, a dog with an artificial heart survives...

for 90 whole minutes.

In 1963 the first patent for an artificial

heart is granted to a man called

Paul Winchell, a ventriloquist -

now there's a novelty act

Winchell’s work is aided by Dr Henry Heimlich -

yes, that Heimlich!

Four years later, a South African called Louis Washkansky

survived for 18 days after the world's

first successful heart transplant.

Only in the 1980s did the procedure become

more successful and widespread and now

300 are carried out in the UK every year.

Did you know that if you take a single

heart cell and put it in a petri dish

it would have a pulse

and if you took one from another heart

it would have a different pulse

but if you then push them together

so that they were touching

they’d synchronise?

That’s kind of beautiful, isn't it?