The Brain in Action

[Music] imagine the coordination needed to perform these complex movements which part of the body is working hardest [Music] the real action happens inside the [Music] head the brain is only a tiny part of you it's smaller than say this cauliflower but the cauliflower doesn't do too much the brain on the other hand is in charge of everything you feel and do this control is possible thanks to a network of tiny Pathways called nerves which run beneath your skin and all over your body tiny electrical signals are hurrying along the nerves towards the brain [Music] for example the hands touch the bar quick as a flash they send off a signal to the brain the message reads this object is cold it's round hard and smooth and we're holding on to it even though the process actually takes only a microsecond we can imagine the signals Journey Through the nerves [Music] [Applause] [Music] when the signal reaches the brain it finds a mass of nerve cells or neurons waiting for the message long fibers or dendrites reach out to pick it up as the signal jumps from one neuron to another it crosses a synapse which in Greek means handshake it's as if the neurons shake hands as this happens the gymnast gets the message from the fingers she feels the bar there are over a billion neurons in one brain if you took a second to count each one you'd be counting for 30,000 years [Music] [Music] this process happens constantly at lightning speeds all over your [Music] body millions of electrical signals carrying messages are zooming through the nervous system and into the brain [Music] this bodytrain communication is being studied at the USC Medical Center electrodes attached to a patient's head measure the electricity in her brain is my friend going to be okay she's going to be just fine what are you doing I'm monitoring her brain wave activity see how busy the brain is now close your eyes Shana your brain is always responding to the things you see anything you feel or even the things you hear open your eyes Jana see how the brain waves change in responds to opening your eyes so the brain's first task is to receive all these Sensations from the body its second task is to process the information and send instructions back out down the nerves maybe it wants the feet to run it sends out the command the brain tells the knees when to bend the legs how to spring the hands where to land before you make any movement your brain performs a thousand calculations about the speed and direction of the move of course you don't think about how to run it just happens but no matter how quickly you move your brain has planned and even rehearsed the movement in a fraction of a [Music] [Music] second we don't think about how to speak or form words either we just open our mouths and talk when we're hungry we simply [Music] eat but without the brain we couldn't say a single word or take a bite of food even tasks like digesting [Music] food circulating the blood or breathing are carried out by the brain a special part called the brain stem takes care of many of these unconscious tasks hey Matt Matt wake up sounds are carried along nerves which lead into the auditory cortex this part of the brain hears wake up wake up hey come on Matt wake up let's go in come on let's go the visual cortex handles everything we see but when the brain has to decide what do we do now the whole cerebral cortex is involved in the decision but what if something goes wrong with this complicated system most of the time Jana is a normal healthy girl but sometimes for short periods her brain waves change dramatically this is because she has a rare brain disease called epilepsy you see how the brain wave activity changes when she's having a seizure she okay yeah she's okay she just doesn't know what's happening Jana can you hear me do you know where you are epilepsy like many other brain diseases is now controllable thanks to drugs produced by medical research but despite scientific progress there's much we still don't know about even a simple rat brain Dr Hernandez investigating these specimens has discovered the cause of a stomach disease he found out that chemicals produce in the brain actually cause stomach ulcers in humans as well as rats with this knowledge he can develop a cure like individual members on a team each part of the brain and body has a separate job to [Music] do but they must collaborate to produce result adults it's no good telling your feet to run if your eyes aren't looking where they're [Music] going this coordination this teamwork between millions of tiny elements is what makes the brain such an effective and marvelous part of Who We Are [Music]