Question: What is the inner clock/ How does it work/How does your body know if it is day or night??? Madscientist2laura

Lilian Hunt answered on 17 Mar 2014:

We seem to have an inner clock called a ‘circadian clock’ that affects us by putting our body through approximately 24 hour cycles, just like a day. This rhythm is internal but can be adjusted by things like daylight. For example if you go on holiday to America, your body eventually adjusts to the new time zone so you are awake in the day and asleep at night. It seems that there is a special group of cells in your brain (in the hypothalamus) that respond to light to cause this cycle. This cycle can affect everything from your brain waves to your body temperature! We believe this is done through hormones being released into your body. It can be useful because if you have trouble sleeping you should sleep with your curtains open so your body naturally responds to day and night cycles 🙂