deep sleep

Directory

References

Discover

Artist interpretation of space asteroids impacting earth and moon. Meteoroids, meteor impact, end of the world, danger, destruction, dinosaur extinct, Judgement Day, Doomsday Predictions, comet

Major Mass Extinctions

Dancers at a Cinco de Mayo festival at the Mission District, San Francisco, California. (Photo dated 2019.) holidays

Is Cinco de Mayo Mexico's Independence Day?

An ancient egyptian hieroglyphic painted carving showing the falcon headed god Horus seated on a throne and holding a golden fly whisk. Before him are the Pharoah Seti and the goddess Isis. Interior wall of the temple to Osiris at Abydos, Egypt.

11 Egyptian Gods and Goddesses

African Americans demonstrating for voting rights in front of the White House as police and others watch, March 12, 1965. One sign reads, "We demand the right to vote everywhere." Voting Rights Act, civil rights.

Timeline of the American Civil Rights Movement

Close up of praying mantis walking on stone ground against a blurred background in Japan

6 Animals That Eat Their Mates

Time zone map with standard time zones and International Date Line

Why Are Some Time Zones 30 Minutes Off Instead of an Hour?

Salem Witch Trials. Photogravure after the painting by Walter McEwen titled - The Witches - circa 1890s.

How Rye Bread May Have Caused the Salem Witch Trials

deep sleep

physiology

Learn about this topic in these articles:

study

In sleep: Light and deep sleep
Which of the various NREM stages is light sleep and which is deep sleep? The criteria used to establish sleep depth are the same as those used to distinguish sleep from wakefulness. In terms of motor behaviour, motility decreases (depth increases) from stages…
Read More