This passage discusses the "fight-or-flight" response that the body uses to escape danger.

Lexile Level: 900L

Categories: Sports & Health

When we lived in more primitive societies, it was sometimes necessary to be able to run very fast to escape dangers. If we could not run, we sometimes had to use physical strength to defend ourselves. Even though we rarely have to run away or fight to save ourselves, our bodies still react to danger in the same way. This response is called the fight-or-flight reaction. Our bodies prepare us to take immediate action. During fight-or-flight reactions, our hearts beat faster and we breathe faster to take in more oxygen. Our bodies produce endorphins, or natural pain relievers. We feel a surge of energy, too, as our bodies use available fat cells and glucose. All of our senses get sharper. We think on a more primitive level and may not use our best judgment. The fight-or-flight reaction may cause us to react in unusual ways.


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