10 Common Digestive Disorders. The spleen is part of the lymphatic system, which plays a role in immunity and maintenance of healthy blood cells. It is an important organ and is affected by disorders of the blood, liver, and immune system. An enlarged spleen is known as splenomegaly. Although hepatosplenomegaly often produces no symptoms, it is known to cause abdominal pain in the upper portion of your abdomen.
NASA is sending astronaut Scott Kelly to live on the International Space Station for a year. That's the longest any U.S. astronaut has spent in space and twice as long as crew members usually stay on the space station. A year is a long time to stay anyplace. But staying a year in space has some special challenges.
EVER WONDERED how astronauts pee in space? Last week, the space shuttle Atlantis blasted off for an 11-day mission to repair the Hubble Space Telescope. In addition to the seven American astronauts on Atlantis, there are three astronauts living and working on the international space station. With 10 humans orbiting Earth, it seemed like as good a time as any to talk about what astronauts do when nature calls. Alan Shepard was the first American to be launched into space. His mission was a 15-minute flight that took place on May 5, 1961, in the Freedom 7 spacecraft.