The Science behind Sleep

Front

What is the term for the naturally occurring physical, behavioral, and mental changes in the body that typically follow the 24-hour cycle of the sun?

Back

circadian rhythm

Front

This group of nerve cells in the brain controls many physiological responses in the body, including the sleep-wake cycle, body temperature, hormone levels, and brain wave activity.

Back

suprachiasmatic nucleus (SCN)

Front

_____ is a type of fatigue that people feel after changing time zones when they travel.

Back

Jet lag

Front

Which hormone released by the pineal gland increases feelings of relaxation and fatigue?

Back

melatonin

Front

The body's biological clock follows the cycle of _____

Back

the sun

Front

During this stage of sleep, you drift in and out of sleep and can be easily awakened.

Back

Stage 1

Front

During this active stage of sleep, your breathing grows irregular, heart rate and blood pressure rise, your eyes dart about beneath your eyelids, and your muscles are temporarily paralyzed.

Back

REM sleep

Front

During this stage of sleep, muscle activity and eye movements completely stop, and you become difficult to awaken.

Back

Stage 4

Front

During what stage of sleep can bursts of intense brain activity called spindles occur?

Back

Stage 2

Front

Which stage of sleep marks the transitional stage between light sleep and deep sleep, when brain wave activity slows?

Back

Stage 3