0:00:03 > 0:00:05Are you ready for Ouch! Snips? Snip!Ouch!Exactly!
0:00:13 > 0:00:16They do everything from pumping blood around your body to
0:00:16 > 0:00:18helping lift your heavy schoolbag.
0:00:18 > 0:00:20Meet Tiny from Tottenham.
0:00:20 > 0:00:25Yep, we've already met.Tiny, put my brother down!Go on, mate.
0:00:25 > 0:00:26Put me down!
0:00:28 > 0:00:31You've got a lot of muscle. Can we have a look at your biceps?
0:00:31 > 0:00:33Chris, not you.
0:00:33 > 0:00:39How big is that bicep?24 inches.24 inches - so that is 61 centimetres.
0:00:39 > 0:00:43That's amazing! So Tiny's bicep is probably bigger than your waist.
0:00:45 > 0:00:48Tiny's muscles are big and very, very strong,
0:00:48 > 0:00:49but what are they made of?
0:00:50 > 0:00:53Well, your muscles are made up of fibres formed from millions of
0:00:53 > 0:00:57individual cells, and blood vessels deliver the energy
0:00:57 > 0:01:00that your muscles need in order to move.
0:01:00 > 0:01:01It's been an absolute pleasure.
0:01:01 > 0:01:04Thank you so much for coming in today.
0:01:04 > 0:01:08Argh!Chris, never be cheeky to a man called Tiny!
0:01:08 > 0:01:10So, how do our muscles actually work?
0:01:10 > 0:01:13Now, your brain controls your muscles by sending a small
0:01:13 > 0:01:15electrical charge down a nerve to the muscle.
0:01:15 > 0:01:17That tells the muscle to move.
0:01:17 > 0:01:19But what happens when we take control away from the brain
0:01:19 > 0:01:23and stimulate the muscle directly with these electrodes?
0:01:23 > 0:01:27I'm attaching electricity-conducting pads to Chris' arms.
0:01:27 > 0:01:29When I press these buttons, electrical charges are sent
0:01:29 > 0:01:33directly to his muscles, which will make his arms move. See?
0:01:33 > 0:01:35That was me!
0:01:35 > 0:01:37Now let's see how many beakers Chris can down
0:01:37 > 0:01:41while I try to override his brain and control his muscles.
0:01:45 > 0:01:46XAND LAUGHS
0:01:46 > 0:01:48Chris is struggling.
0:01:52 > 0:01:54BUZZER SOUNDS
0:01:54 > 0:01:57You can't... You can't... You cannot let go!Just put it down.
0:01:57 > 0:01:59So, we know what makes your muscles move,
0:01:59 > 0:02:01but how do your muscles make your bones move?
0:02:01 > 0:02:04Well, it wouldn't happen without your tendons.
0:02:04 > 0:02:06To show you how tendons move your bones,
0:02:06 > 0:02:12I have invented this - a model arm made of space-age materials!
0:02:12 > 0:02:15Xand, this is something made of cardboard, a bit of string
0:02:15 > 0:02:19and some straws.They use all of those things in space!
0:02:19 > 0:02:22Now, this is the muscle, this is the bone,
0:02:22 > 0:02:26and this piece of string is the tendon connecting the two of them.
0:02:26 > 0:02:30Now, when I take this balloon, put it in here and inflate it...
0:02:31 > 0:02:32Wow!
0:02:32 > 0:02:36When Xand inflates the balloon, it's like my muscle contracting,
0:02:36 > 0:02:39and it pulls on the tendon and moves the bone.
0:02:39 > 0:02:42Your tendons have to be strong so that they can lift
0:02:42 > 0:02:45and move your bones and anything else you're carrying.
0:02:45 > 0:02:50The strongest and thickest tendon in your body is the Achilles tendon.
0:02:50 > 0:02:52And it... What have I told you about shoes in the lab?
0:02:52 > 0:02:56I thought everyone would like to see my Achilles tendon! It's right here.
0:02:56 > 0:02:59It connects my calf to my heel.
0:02:59 > 0:03:00Do you know, Chris,
0:03:00 > 0:03:03your Achilles tendon is meant to be stronger than steel?
0:03:03 > 0:03:07It's just a shame we don't have any way to test that in the lab.
0:03:07 > 0:03:10Well, Xand, I actually have the perfect experiment for this,
0:03:10 > 0:03:12but we do need to head outside.
0:03:12 > 0:03:15And you're going to need this.
0:03:15 > 0:03:16Meet...
0:03:20 > 0:03:21Let's go find out how it works.
0:03:22 > 0:03:25This is a horse's tendon.
0:03:25 > 0:03:28These are scientists from Queen Mary University of London.
0:03:28 > 0:03:31They're attaching these clamps to the horse tendon, which is
0:03:31 > 0:03:34then frozen with dry ice.
0:03:34 > 0:03:36Let's test how strong this tendon really is,
0:03:36 > 0:03:39but maybe we should start with something small.
0:03:39 > 0:03:43Well, what about Zahara? She's right here!Oh, hi, Zahara!
0:03:43 > 0:03:47Hi, Chris.Well, sounds like it's time for some tendon-powered flight!
0:03:47 > 0:03:48Get in the bag! Come on.
0:03:50 > 0:03:55Are you strapped in?Yep.Helmet on? Yes.Great stuff.Good luck!
0:03:55 > 0:03:56We'll see you when you land!
0:03:56 > 0:03:57Yeah.
0:03:57 > 0:04:00Remember, Zahara's body weight is being supported
0:04:00 > 0:04:04only by the horse tendon, but will it hold?
0:04:04 > 0:04:06Three, two, one...
0:04:06 > 0:04:08BOTH:Liftoff!
0:04:11 > 0:04:12You're airborne!Whoo!
0:04:15 > 0:04:19That one small tendon is holding the full weight of Sahara.
0:04:19 > 0:04:21That's amazing.
0:04:21 > 0:04:24We're going to push this horse's tendon to the limit and see if it's
0:04:24 > 0:04:28strong enough to take the weight of not one of us but both of us!
0:04:28 > 0:04:31You guys are crazy!
0:04:31 > 0:04:36BOTH:Three, two, one... Liftoff!
0:04:36 > 0:04:37Whoa!Whoa!We're off!
0:04:38 > 0:04:43This is incredible! The only thing holding us up is a horse tendon!
0:04:44 > 0:04:50Wow! That one little tendon is taking our combined weight of 180kg.
0:04:50 > 0:04:52It really is as strong as steel.
0:04:53 > 0:04:56See you next time. Bye!Bye!
0:04:56 > 0:04:59Bye.Bye.Bye!Bye.Bye!
0:05:00 > 0:05:02NO SOUND