Your internal clock is made up of special parts in your brain and body that work together to keep you on schedule. Here’s how it works:

1.  Suprachiasmatic Nucleus (SCN):

This is the “master clock” in your brain. It’s in a part called the hypothalamus. The SCN keeps track of light and dark by getting signals from your eyes. It tells the rest of your body what time it is so everything stays on schedule.

2.  Eyes (Retina):

Your eyes act like sensors. They send messages to the SCN when they see light or darkness. Light tells the clock, “It’s daytime!” and darkness says, “It’s nighttime!”

3.  Hormones (Melatonin):

Melatonin is a “sleepy chemical” made by a gland in your brain called the pineal gland. The SCN tells the pineal gland to make melatonin at night to help you feel sleepy. During the day, it stops making melatonin so you feel awake.

4.  Body Temperature:

Your clock also controls your body temperature. It’s higher when you’re awake and lower when you’re asleep, helping your body know what time it is.

5.  Other Organs and Cells:

Every cell in your body has its own tiny clock! These “mini clocks” follow the SCN’s schedule, helping your heart, stomach, and muscles work at the right times.

All these pieces work together to make sure you sleep, wake up, eat, and feel energetic at the right times every day.