Astronaut physiology

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Astronaut: a man or woman whose job it is to fly in space. Astronauts are usually really good at math and science, and aren't scared of sitting on top of rockets.

Glamorous: something exciting and attractive.

Gravity: the attraction of one body to another. Gravity gives objects weight and causes them to fall to the ground if dropped... more

Lymph: a fluid that circulates through your body, helping to fight infections.

Frenzied Fluids

Space may sound glamorous, but living in space changes the way you look, and in space you should never stray too far from a bathroom. Gravity affects water and lymph, fluids found in our bodies. Lymph helps our bodies fight against sicknesses like the cold or flu and other infections.

Fluid movement in body

A diagram showing fluid movement in the body.

On Earth, fluids are being pulled down by gravity, and our muscle movement helps to move them back up. In space, because body fluids aren’t pulled down by gravity, they collect around the chest and head.

The upper body swells, and astronauts get what’s called “puffy face.” Because fluids don’t move around the body as well as when on Earth, these pools of fluid fool the body, making it think it is carrying too much water. This makes the astronauts have to pee a lot. In space, astronauts pee more and drink less, so they can become dehydrated very easily.

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Bibliographic details:

  • Article: Frenzied Fluids
  • Author(s): Amy Shira Teitel
  • Publisher: Arizona State University School of Life Sciences Ask A Biologist
  • Site name: ASU - Ask A Biologist
  • Date published: December 8, 2011
  • Date accessed: May 15, 2024
  • Link:

APA Style

Amy Shira Teitel. (2011, December 08). Frenzied Fluids. ASU - Ask A Biologist. Retrieved May 15, 2024 from

American Psychological Association. For more info, see

Chicago Manual of Style

Amy Shira Teitel. "Frenzied Fluids". ASU - Ask A Biologist. 08 December, 2011.

MLA 2017 Style

Amy Shira Teitel. "Frenzied Fluids". ASU - Ask A Biologist. 08 Dec 2011. ASU - Ask A Biologist, Web. 15 May 2024.

Modern Language Association, 7th Ed. For more info, see
International Space Station Crew members

In space, it is easy to become dehydrated. Here astronauts show off special drink containers.

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