Your Body Clock: Why You Get Sleepy at Night
Even with no clock in the room, your body knows when it is time to sleep. Deep inside your brain is a tiny timer that keeps track of the whole day. When the sky gets dark, your body makes a sleepy helper called melatonin that whispers: time for bed!
What You'll Learn
You will learn that your body has a clock inside it. You will learn how light and dark set that clock. You will learn how sleep helps you grow and remember.
Your Body Has a Clock Inside
Your body clock runs all day and all night, about every 24 hours. Grown-up scientists call this a circadian rhythm. It makes you feel wide awake in the morning and sleepy at night, even before anyone tells you what time it is.
Light Says Wake, Dark Says Sleep
Your eyes tell your brain if it is light or dark outside. Bright morning light says 'wake up and play!' Dark evening says 'slow down and rest.' That is why bright screens at night can trick your body into staying awake when it should be getting sleepy.
Why Sleep Helps You
While you sleep, your body grows a little and fixes itself. Your brain also tucks away the things you learned that day, like a new word or a song. That is why you can feel grumpy and forgetful on days when you did not sleep enough.
Turn the lights down low and put screens away before bed. Soft, dark, and quiet tells your body clock that sleepy time is here.
Drag each thing to the time of day it belongs to.
Terms
Definitions
Drag terms onto their definitions, or click a term then click a definition to match.
What does your body make when it gets dark to help you feel sleepy?
Why is it hard to fall asleep with bright screens right before bed?
Draw Your Day and Night
Fold a paper in half. On one side draw a sun and things you do when your body clock says it is DAY, like eating breakfast and playing. On the other side draw a moon and things for NIGHT, like brushing teeth and sleeping. Show a grown-up and tell them one way you help your body get sleepy.
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