The body´s clock

A pattern that repeats every day

• insomnia

• melatonin

• Circadian rhythm

trouble sleeping

• insomnia

• reset

• retina

a tired feeling caused by long-distance plane travel

• jet-lag

• retina

• time zone

a chemical that makes you fell sleepy

• melatonin

• insomnia

• circadian rhythm

a stage of deep sleep when dreams happen

• REM sleep

• reset

• time zone

to move back to an original position

• retina

• REM sleep

• reset

a part of the human eye

• time zone

• retina

• insomnia

one of the twenty-four sections of Earth with its own time

• retina

• jet-lag

• time zone