0:00:02 > 0:00:04- Are you ready for our Ouch Snips? - Snip!- Ouch! Exactly.
0:00:09 > 0:00:13Did you know there are around 60km of nerves in the human body?
0:00:13 > 0:00:17They carry signals all over the body in super quick time. But how?
0:00:19 > 0:00:21This is a spinal column
0:00:21 > 0:00:24and it runs all the way from the bottom of your head
0:00:24 > 0:00:26to the top of your bottom.
0:00:27 > 0:00:32Now, this spinal column is from a pig, but yours is very similar.
0:00:32 > 0:00:35The whole structure is designed to protect a very important bunch of
0:00:35 > 0:00:37nerves called the spinal cord,
0:00:37 > 0:00:40and it runs down this groove in the middle.
0:00:40 > 0:00:43And this is the spinal cord itself.
0:00:43 > 0:00:47The reason that it's so well protected inside those bones is
0:00:47 > 0:00:48because it's very important -
0:00:48 > 0:00:52it carries all the information from your brain to your muscles.
0:00:52 > 0:00:53And what's really amazing is,
0:00:53 > 0:00:56some nerves carry signals at 100 metres per second...
0:00:58 > 0:01:02..which is 10 times faster than anyone can run - even Usain Bolt.
0:01:02 > 0:01:05So how are they so fast? Well, we're going to show you.
0:01:05 > 0:01:07BELL RINGS
0:01:07 > 0:01:09Hang on, that's the lunch bell! Woohoo!
0:01:13 > 0:01:15Just a minute, Xand, it's not lunchtime yet.
0:01:15 > 0:01:17What's everyone doing in the canteen?
0:01:20 > 0:01:23Erm, Xand, what on earth is going on?
0:01:23 > 0:01:26It's actually part of a plan to show you how nerves work.
0:01:26 > 0:01:30Now, the lunch queue represents one single nerve.
0:01:30 > 0:01:32All the way along the nerve are ion channels,
0:01:32 > 0:01:34and that's what the people in this lunch queue are.
0:01:34 > 0:01:37They pass the message from one place to another,
0:01:37 > 0:01:39all along the length of the nerve.
0:01:39 > 0:01:40OK, I see.
0:01:40 > 0:01:42So I represent my own brain,
0:01:42 > 0:01:44and I'm thirsty and I want a cup of tea,
0:01:44 > 0:01:47but in order to get my hand to get me a cup of tea,
0:01:47 > 0:01:49I have to send a message down this line,
0:01:49 > 0:01:52just like the brain would send a nerve single down a nerve.
0:01:53 > 0:01:56So, my brain is using the ion channels in my nerve to send
0:01:56 > 0:01:58a message to my hand for a drink.
0:01:58 > 0:02:00Hmm, tea.
0:02:00 > 0:02:02OK. Milk, two sugars, please.
0:02:02 > 0:02:04Thank you.
0:02:04 > 0:02:06Ooh, this tea is very hot.
0:02:06 > 0:02:09I'd better send a note to Chris's brain to see what he wants me
0:02:09 > 0:02:11to do about it.
0:02:11 > 0:02:13Hurry up, ion channels - this is really hot!
0:02:13 > 0:02:15Aaarrrgh!
0:02:16 > 0:02:18"Tea is too hot."
0:02:18 > 0:02:21Hmm, Well, Xand's message did eventually get to me but it
0:02:21 > 0:02:23took a long time, didn't it?
0:02:23 > 0:02:25Well, from my perspective, the tea is too hot to drink
0:02:25 > 0:02:26so I'm going to go back to the lab.
0:02:26 > 0:02:29Come on, ion channels.
0:02:29 > 0:02:30Uh, Chris?
0:02:31 > 0:02:33Chris?
0:02:34 > 0:02:37Thankfully, your nerves have a trick up their sleeves to make them
0:02:37 > 0:02:40work a whole lot better than our lunch queue,
0:02:40 > 0:02:43and we're going to show you just what that is by using dominoes.
0:02:43 > 0:02:46Dominoes? Great!
0:02:46 > 0:02:49Now, each line of dominoes represent a single nerve and each
0:02:49 > 0:02:52domino is an ion channel, just like those people in the lunch queue.
0:02:52 > 0:02:57Now, in this line-up, all the dominoes are side-by-side.
0:02:57 > 0:03:01But in this line-up, there are rulers between each domino,
0:03:01 > 0:03:03and these rulers represent something called a...
0:03:06 > 0:03:07Now, in your body, there is
0:03:07 > 0:03:10a myelin sheath wrapped around many of your nerves.
0:03:10 > 0:03:12This is what allows messages to travel down your nerves
0:03:12 > 0:03:14in a very special way.
0:03:14 > 0:03:17Both cars will go round the loop but...
0:03:17 > 0:03:19Which car is going to jump first?
0:03:19 > 0:03:21Let's find out. It's time for a...
0:03:25 > 0:03:28Wearing blue in lane one, it's the Rampaging Ruler,
0:03:28 > 0:03:32the Myelin Sheath Mover, Dr Chris!
0:03:32 > 0:03:37And in lane two, the Green Machine, the Domino Dominator, Dr Xand!
0:03:37 > 0:03:39Drivers at the ready!
0:03:39 > 0:03:41Three, two, one, go!
0:03:45 > 0:03:46YES!
0:03:46 > 0:03:47Let's see that again!
0:03:48 > 0:03:51What a start from Dr Chris's myelin sheath as it
0:03:51 > 0:03:54streaks ahead of Dr Xand's dawdling dominoes.
0:03:56 > 0:03:59Exactly what happens inside your body is the myelin sheath
0:03:59 > 0:04:03wrapped around the nerve allows the signal to go superfast
0:04:03 > 0:04:06and sends the blue car speeding to the finish.
0:04:06 > 0:04:09It's just as well because if your nerves were like Xand's race,
0:04:09 > 0:04:11you'd be the slowest-moving human on the planet.
0:04:11 > 0:04:13Oi!
0:04:14 > 0:04:17So, we've shown you the amazing superhighway of nerves that is
0:04:17 > 0:04:19your spinal cord.
0:04:19 > 0:04:21And we've shown you how they pass messages around your body
0:04:21 > 0:04:24so quickly, at 100 metres per second.
0:04:24 > 0:04:27And that's all thanks to a layer of fat called the myelin sheath
0:04:27 > 0:04:30which allows messages to jump along the nerve,
0:04:30 > 0:04:33getting to their destination superfast.
0:04:34 > 0:04:37- Right, I want to have a rematch. - Fine, we can.
0:04:37 > 0:04:40- But you have to set up the dominoes. - No problem at all, OK, good.
0:04:40 > 0:04:42Now, this time, I'm going to want the other line-up.
0:04:42 > 0:04:45I wonder if I can get rid of some of these blue dominoes.
0:04:47 > 0:04:49Ohhh!
0:04:49 > 0:04:51- See you next time!- Bye!- Bye!
0:04:51 > 0:04:53- Bye!- Bye!- BYE!
0:04:53 > 0:04:55- Bye!- BYEEE!