March 15, 2005

How Does Living in Space Affect Your Body?

Being able to float in space looks like a lot of fun, but the down side is the effect on the body of low gravity. For a start the body fluids float up, making the body appear fatter and bloated.To overcome this astronauts wear straps around the top of their legs.Fluids including plasma are lost from the body.Plasma is the straw coloured 'liquid' part of blood in which red blood cells, white blood cells and platelets are suspended.

Put in blood image

Living in space also reduces the number of red blood cells. Because of this less oxygen is carried to the body cells.This means the cells' capacity to produce energy in respiration will also be reduced.

Loss of bone mass is another disadvantage of low gravity in space.Studies on astronauts in the Mir space station showed that 1 to 2% of bone mass was lost every month.This makes the bones weak and the astronauts can find it difficult to walk when they return to earth.

Astronauts aren't the only people who have to be concerned about bone loss.Many people suffer from bone loss in a condition known as osteoporosis.

Research shows that exercise helps keep bones and muscles healthy.

How do astronauts exercise in space?

In space astronauts can exercise in a number of ways. They can use a cycle ergometer which you pedal like a bicycle. They can also use a treadmill but they have to be strapped in to stop them floating away.

Can they use a weight lifting machine? Can you think of an alternative?


Using the information in the passage above and in your science books answer the following questions:

Space Biology1. Name the four components of blood.2. What is the function of each component?3. Write the word equation for respiration.4. Look at the diagrams of two human blood cells below.

(a) Name each type of cell.(b) Which of the cells:- Contains haemoglobin?- Can pass through capillary walls?- Transports oxygen?- Digests bacteria?

5. What nutrients should an astronaut be encouraged to eat before and during a space flight to ensure strong bones?6. Why would an iron supplement be useful to astronauts when they return to Earth?7. How many calories does an astronaut need per day? Find out your energy requirement and discuss why energy requirement varies from person to person.8. Exercise is very important to astronauts.What benefits can exercise have in our lives?9. Many scientists are studying how to grow plants in space craft. Give three reasons why this is important to space flight. 10. Prepare a poster about one aspect of biology in space.