
The stimulus of gravity affects RNA production, which helps maintain the strength of human muscles on Earth (top), as seen in this section of muscle fiber taken from an astronaut before spaceflight. Astronauts in orbit and patients on Earth fighting muscle-wasting diseases need countermeasures to prevent muscle atrophy, indicated here with white lipid droplets (bottom) in the muscle sample taken from the same astronaut after spaceflight. Kerneth Baldwin of the University of California, Irvine, is conducting research on how reducing the stimulus of gravity affects production of the RNA that the body uses as a blueprint for making muscle proteins. Muscle proteins are what give muscles their strength, so when the RNA blueprints aren't available for producing new proteins to replace old ones -- a situation that occurs in microgravity -- the muscles atrophy. When the skeletal muscle system is exposed to microgravity during spaceflight, the muscles undergo a reduced mass that translates to a reduction in strength. When this happens, muscle endurance decreases and the muscles are more prone to injury, so individuals could have problems in performing extravehicular activity [space walks] or emergency egress because their bodies are functionally compromised.
Most NASA images are in the public domain and free to use. Credit NASA as the source. Check NASA's media usage guidelines for details. Images featuring identifiable individuals may require additional permissions.
NASA ID
0300206
Date Created
January 22, 2003
Center
MSFC
Media Type
image
Download this image in multiple resolutions. All NASA media are free for public use.
1920px