• Question: why do humans sleep

    Asked by reaganbrien to Ben, Dave, Ed, Sam, Susana on 25 Jun 2013.
    • Photo: Sam Horrell

      Sam Horrell answered on 25 Jun 2013:


      This is yet another we still actually don’t know answer, but there are a few ideas.

      One is that it allows us to repair cells damaged by free radicals (really reactive molecules that damage DNA). They think this because of DNA repair genes being activated while we sleep. Another theory is that it allows us to replenish out fuel. We use a molecule called ATP for most of our energy, when this gets low that tells the body it needs to sleep.

      The third theory is that it allows you to do a little housekeeping in your brain, sorting out all the new synpases your brain has been making throughout the day. Finally the fourth theory is that it allows you to replay the day help with making memories and such.

      It may be a combination of all four of these or there may be more we don’t know about yet.

    • Photo: David Briggs

      David Briggs answered on 25 Jun 2013:


      Because that is just how we evolved.

      Sleep gives us time to rest, repair, and regenerate. At a cellular level, we have an internal clock (called the circadian rhythm) which governs all sorts of different aspects of how our cells work – and during sleep periods our cells have a chance to restock supplies of nutrients and get ready for another days action.

    • Photo: Susana Teixeira

      Susana Teixeira answered on 26 Jun 2013:


      As Sam and Dave already mentioned, scientists think there is a number of reasons. When we sleep this imposes a period of lower physical activity during which our body can for example repair and form new muscle or regulate its hormone levels.
      The other important thing about sleeping is that it is very good for our brain! It collects a lot of information that it needs to process, so at this point it can reorganise itself better while it is not receiving new information. You can also dream, which is again another complicated process but, among other things, it allows you to rehearse situations you may encounter while awake.

      So in the end it’s like a restart on your computer to get rid of all those pending processes and get new programs started, except in our case we take a few hours to get back to our login screen 🙂

Comments