• Question: how do we move

    Asked by anon-267030 on 30 Oct 2020.
    • Photo: Paola Galdi

      Paola Galdi answered on 30 Oct 2020: last edited 30 Oct 2020 11:52 am


      There is a special part of the brain that is in charge of planning and controlling the movements we decide to make, the motor cortex, which is located roughly where you would wear a hairband or your headphones.

      In order to move, the brain controls our muscles, that contract and relax according to the instructions they receive from the brain. These instructions need to travel from the brain to every muscle in your body, from the head up to your little toes.

      They do so using the neural system, which is like a railway connecting brain and body, where the rails are made of nerves (long threads able to transmit electricity) and the trains carrying the instructions are electrical impulses generated in the brain. They travel so fast that we are not able to perceive the delay between the time we decide to move and when we actually move, but it actually takes a (small) fraction of a second.

    • Photo: Vrushali Patil

      Vrushali Patil answered on 30 Oct 2020:


      What an interesting question! As we are on Earth (which is always moving around the Sun), I suppose even when we sit still we are ‘moving’. And while sitting or standing in one place, our bodies have several things happening inside that keep it ‘moving’ – our hearts are beating constantly, we are breathing in and out thus moving our chest, our nerves are twitching, our eyelids are moving while blinking. In order to reach a different place, I suppose we move by walking, which involves lifiting one foot, changing its location and then letting the other foot follow it. This allows our whole body to ‘move’ from a location to another. When done continuously, depending on the speed, we can either walk or run too!

    • Photo: Rob Mahen

      Rob Mahen answered on 30 Oct 2020:


      One way humans move is using muscles – tissues that push and pull against bones and tendons to move all different parts of us. Inside muscles are specialised long proteins that use energy stored in the body to move against each other.

      Muscles can change in response to more or less movement, which is one reason why keeping active by moving makes us fit and healthy.

    • Photo: Thomas Williams

      Thomas Williams answered on 3 Nov 2020:


      Pairs of muscles pull our bones backwards and forwards when told to by the brain.

      The brain can make the muscles move faster and slower, like running and walking, and can be actively controlled by you (like running and walking!), or can just happen in the background (like digesting food).

    • Photo: Guy Yona

      Guy Yona answered on 3 Nov 2020: last edited 3 Nov 2020 8:06 pm


      The decision to move arises somewhere in the brain, maybe in response to an incoming ball entering our field-of-view, or maybe we were just sitting for too long in the same position on our couch. That decision reaches several regions in the brain: one of them, the motor cortex (see Paula’s beautiful explanation for where it is!), is responsible for making out the details of the movement – how exactly are our hands going to reach that incoming ball. Another region, the “basal ganglia” is helping to determine how strong is the movement going to be, or maybe it might decide to drop the idea altogether (is this jump going to bring the winning score, or are you surely loosing and it wouldn’t be worth the fall?). Many other parts of the brain pitch in as well, and eventually a set of motor commands travel down our spine. All that planning takes quite a while, about a tenth of a second, even a bit longer if the ball comes in a funny angle!

      Inside our spines, there are groups of brain cells that specialise in making sense of these instructions coming down from the brain. These groups of cells are part of the spinal cord, and each group is responsible for a specific set of muscles. For example, the cells that control our hands are located in the back of our necks, and those that control our legs are in the lower back. It all makes perfect sense. The largest and strongest of cells in these groups have very long “wires” coming out of them that bundle together into nerves. These nerves, which look like thin white wires, exit the spine through special openings, and travel inside the body all the way to the muscle they operate.

      Why “the largest and strongest cells”, you might ask? These cells, which we can’t even see without a microscope, need to send electrical signals a long way through their nerves, that branch out to cover a huge muscle (like the thigh muscle), and “tell” it to contract. When the electrical signals reach nerve endings that touch the muscles, they release a chemical called “Acetylcholine”, which is being picked up by the muscle cells. As they sense this acetylcholine, a chemical chain of events occurs that causes the muscle cell to contract. Since many muscle cells are controlled by a single nerve cell, they contract together, like rowers pulling together their oars, and the whole muscle contract. The muscles connect to the bones by flexible rope-like “tendons”, so when they contract – the bone moves.

      Pffww… that was.. not all. You wouldn’t think the brain just issues commands without following through? Special sensors in the muscles and tendons monitor every small movement, and send that information back to the spinal cord by a different set of nerves, where it is being used to refine the movements, and back to the brain. The brain compares what we wanted to do with what we actually did, and learns – so next time, it will be better. So, if you missed that ball now, keep practicing!

    • Photo: Anitta Chacko

      Anitta Chacko answered on 3 Nov 2020: last edited 3 Nov 2020 4:10 pm


      Great question! I’ve too always wondered how I’m actually able to pull of some awesome dance moves or run as fast as I can down the stairs as soon as my pizza delivery has arrived and really the answer lies within us! When you decide its time to dance or run or even to lift a pizza slice into your mouth, your brain acts like a solider, giving commands to different parts of your body such as your muscles.

      These commands also known as signals travel through the nervous system. In the case of eating your pizza, the brain will tell your muscles in your hands and wrists to contract and by doing so you’re able to grab that delicious pizza slice. Your brain will then send more signals telling the muscles in your arm to move so that the pizza slice can be moved to your mouth and hey presto your eating your pizza! These signals travel so fast from your brain that it hardly takes any time for you to pick up your pizza slice. As you get much much older, these signals cannot travel as fast from your brain to your muscles leading to slower movement.

      So really its the communication between your brain and the signals that reach your muscles that allow your body to move. I hope that helped clear things up a little!

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