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15.1 What Are Circadian Rhythms?

1.
The field of ________ studies biological clocks and biological rhythms within an organism.
2 .
Sleep cycles during the night are an example of ________ rhythms and have periods significantly shorter than 24 hours.
3.
________ is a term used to describe how an organism’s internally generated rhythm is synchronized to the rhythms of the external environment.

15.2 Where Are Rhythms in the Brain?

4 .
The ________ of the hypothalamus and is considered to be the master clock of the brain.
5.
In the presence of light, the pineal gland will reduce secretion of ________ into the bloodstream.

15.3 Regulation of Sleep

6 .
Stage ________ non-REM sleep is characterized by deep sleep, muscle relaxation, slowed breathing, and EEG delta waves.
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