Episode 4 Operation Ouch!

-Are you ready for our Ouch Snips?

-Snip!

-Ouch! Exactly.

Did you know there are around 60km of nerves in the human body?

They carry signals all over the body in super quick time. But how?

This is a spinal column

and it runs all the way from the bottom of your head

to the top of your bottom.

Now, this spinal column is from a pig, but yours is very similar.

The whole structure is designed to protect a very important bunch of

nerves called the spinal cord,

and it runs down this groove in the middle.

And this is the spinal cord itself.

The reason that it's so well protected inside those bones is

because it's very important -

it carries all the information from your brain to your muscles.

And what's really amazing is,

some nerves carry signals at 100 metres per second...

..which is 10 times faster than anyone can run - even Usain Bolt.

So how are they so fast? Well, we're going to show you.

BELL RINGS

Hang on, that's the lunch bell! Woohoo!

Just a minute, Xand, it's not lunchtime yet.

What's everyone doing in the canteen?

Erm, Xand, what on earth is going on?

It's actually part of a plan to show you how nerves work.

Now, the lunch queue represents one single nerve.

All the way along the nerve are ion channels,

and that's what the people in this lunch queue are.

They pass the message from one place to another,

all along the length of the nerve.

OK, I see.

So I represent my own brain,

and I'm thirsty and I want a cup of tea,

but in order to get my hand to get me a cup of tea,

I have to send a message down this line,

just like the brain would send a nerve single down a nerve.

So, my brain is using the ion channels in my nerve to send

a message to my hand for a drink.

Hmm, tea.

OK. Milk, two sugars, please.

Thank you.

Ooh, this tea is very hot.

I'd better send a note to Chris's brain to see what he wants me

to do about it.

Hurry up, ion channels - this is really hot!

Aaarrrgh!

"Tea is too hot."

Hmm, Well, Xand's message did eventually get to me but it

took a long time, didn't it?

Well, from my perspective, the tea is too hot to drink

so I'm going to go back to the lab.

Come on, ion channels.

Uh, Chris?

Chris?

Thankfully, your nerves have a trick up their sleeves to make them

work a whole lot better than our lunch queue,

and we're going to show you just what that is by using dominoes.

Dominoes? Great!

Now, each line of dominoes represent a single nerve and each

domino is an ion channel, just like those people in the lunch queue.

Now, in this line-up, all the dominoes are side-by-side.

But in this line-up, there are rulers between each domino,

and these rulers represent something called a...

Now, in your body, there is

a myelin sheath wrapped around many of your nerves.

This is what allows messages to travel down your nerves

in a very special way.

Both cars will go round the loop but...

Which car is going to jump first?

Let's find out. It's time for a...

Wearing blue in lane one, it's the Rampaging Ruler,

the Myelin Sheath Mover, Dr Chris!

And in lane two, the Green Machine, the Domino Dominator, Dr Xand!

Drivers at the ready!

Three, two, one, go!

YES!

Let's see that again!

What a start from Dr Chris's myelin sheath as it

streaks ahead of Dr Xand's dawdling dominoes.

Exactly what happens inside your body is the myelin sheath

wrapped around the nerve allows the signal to go superfast

and sends the blue car speeding to the finish.

It's just as well because if your nerves were like Xand's race,

you'd be the slowest-moving human on the planet.

Oi!

So, we've shown you the amazing superhighway of nerves that is

your spinal cord.

And we've shown you how they pass messages around your body

so quickly, at 100 metres per second.

And that's all thanks to a layer of fat called the myelin sheath

which allows messages to jump along the nerve,

getting to their destination superfast.

-Right, I want to have a rematch.

-Fine, we can.

-But you have to set up the dominoes.

-No problem at all, OK, good.

Now, this time, I'm going to want the other line-up.

I wonder if I can get rid of some of these blue dominoes.

Ohhh!

-See you next time!

-Bye!

-Bye!

-Bye!

-Bye!

-BYE!

-Bye!

-BYEEE!