How dangerous is the environment of the universe and what effect will it have on the human body? A paper in Science Progress shows that 1 1 astronauts' brains shrink after a long weightless flight in space.
Scientists from Australia, Belgium, Germany and Russia studied and analyzed the brain structure of 1 1 Russian astronauts.
The average stay time of the astronauts participating in the research on the International Space Station is 17 1 day, which is nearly 6 months. Although they are not always exposed to space, they will also be affected in the space station.
Scientists performed diffusion magnetic resonance imaging on each astronaut three times, 1 time before entering space and twice after returning from space.
During the analysis, the research team noticed that the structure and function of human brain will change before and after space flight.
In the zero gravity environment, the distribution of white matter and gray matter in the brain has changed, the ventricle has become larger and the cerebrospinal fluid has become more. Scientists believe that this change occurs because the nervous system is adapting to weightlessness in this way.
It should be noted that the changes made by these astronauts are not permanent. Seven months after they returned to Earth, all indicators returned to normal.
In fact, scientists have explored the effects of space flight on the human brain before. In 20 17, a study by the university of Michigan showed that astronauts' brains would compress and expand during flight.
The research team analyzed the data of 26 astronauts who received brain magnetic resonance imaging (MRI) after returning to Earth. The results showed that the volume of gray matter in different areas of their brains increased or decreased.
The researchers said that most of the decrease in gray matter volume may be due to the spatial redistribution of cerebrospinal fluid.
Scientists' research shows that space flight has a great influence on the human body, not only the brain, but also many other aspects, such as height and eyes.
Living in the International Space Station for a month will make you a little taller. In weightlessness, the height of astronauts in space will increase by 3%. If a person is about 1.8 meters, then he can grow about 5 centimeters tall.
Astronaut Michael Barrett needs to wear glasses to see distant things before performing space missions; But when he comes back from his mission, he has to wear reading glasses to see everything nearby.
However, these changes in height and visual system are not permanent. A few months after returning to earth, the astronauts' height will return to normal.
In addition, in space, some muscles of the human body will experience muscle atrophy, deformation and even tissue degeneration. The longer you live in space, the more obvious these muscles atrophy.
NASA once conducted a twin astronaut experiment.
In the plan, NASA astronaut scott kelly will stay in the space station for one year; Scientists will collect his genetic, molecular and physiological data.
Scott has a twin brother named mark kelly. He is also an astronaut, but he has retired and spent much less time in space.
After scientists collect Scott's data, they will compare it with Mark's data, find out the differences and find the answers to extreme environments.
Finally, this experiment produced 10 research projects, including changes in cognitive ability and gene expression.
However, the press release issued by NASA was seriously misunderstood by some media, which led to the emergence and spread of rumors.
In a press release, NASA said that after Scott returned to Earth, 93% of the genes recovered as usual, while the remaining 7% may lead to long-term changes in genes related to immune system, DNA repair, bone formation network, hypoxia and hypercapnia.
The press release doesn't specify what "genetic change" is, so some people think that 7% of Scott's DNA has been permanently changed.
In fact, Scott was changed by gene expression, not DNA. After realizing that the wording of its press release was not rigorous enough, NASA updated the press release, emphasizing that Scott's genes had not changed fundamentally.
Moreover, the gene expression of 7% has not changed much, which belongs to the normal range.
As we all know, the radiation in the universe is very strong, even in the space station, astronauts who perform tasks can't completely avoid radiation.
There used to be a saying that "female astronauts are forbidden to give birth after returning to earth", which is actually a rumor and can't stand any scrutiny.
In fact, after returning to China, female astronauts will not only be forbidden to give birth, but also will not have fertility problems because of space flight.
For example, Valentina Tereshkova, the first female astronaut in human history, just got married more than four months before going into space.
The next year, the astronaut gave birth to a baby girl. This baby girl is not only beautiful, but also smart, and later became a doctor.
In addition to valentina, there are also examples in China that can break this rumor, that is, Liu Yang, China's "first female astronaut", gave birth to a child after returning to Earth from a space mission.
Space is not a comfortable environment for human beings. Without oxygen for breathing, the microgravity environment will kill bones and muscles, and the human body will also be irradiated by a large number of high-energy charged particles, leading to cell damage.
It can be said that astronauts really risked their lives to carry out space missions. It is the wisdom of countless people that they can successfully complete their mission and return home dressed in rags, which deserves our admiration.
When collecting relevant information, I saw a friend ask: Since it is so dangerous, why should we explore space? How nice it is to stay on earth.
What wormhole wants to say is that manned space flight is a comprehensive frontier science and technology, which has an important impact on the world economy and science, and is also one of the standards to measure a country's comprehensive national strength.
Moreover, any exploration of the unknown is bound to be accompanied by possible dangers, but what we should do is not to stop there, but to "increase defense" and try our best to avoid risks.
In addition to exploring the universe, we should learn to look up at the stars and keep our feet on the ground, so as to have a brighter future.
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