| 翻訳と辞書 |
| Neuroscience in space ： ウィキペディア英語版 |
Neuroscience in space
Space neuroscience is the scientific study of the central nervous system (CNS) functions during spaceflight. Living systems can integrate the inputs from the senses to navigate in their environment and to coordinate posture, locomotion, and eye movements. Gravity has a fundamental role in controlling these functions. In weightlessness during spaceflight, integrating the sensory inputs and coordinating motor responses is harder to do because gravity is no longer sensed during free-fall. For example, the otolith organs of the vestibular system no longer signal head tilt relative to gravity when standing. However, they can still sense head translation during body motion. Ambiguities and changes in how the gravitational input is processed can lead to potential errors in perception, which affects spatial orientation and mental representation. Dysfunctions of the vestibular system are common during and immediately after spaceflight, such as space motion sickness in orbit and balance disorders after return to Earth.
Adaptation to weightlessness involves not just the Sensory-motor coupling functions, but some autonomic nervous system functions as well. Sleep disorders and orthostatic intolerance are also common during and after spaceflight. There is no hydrostatic pressure in a weightless environment. As a result, the redistribution of body fluids toward the upper body causes a decrease in leg volume, which may affect muscle viscosity and compliance. An increase in intracranial pressure may also be responsible for a decrease in near visual acuity. In addition, muscle mass and strength both decrease as a result of the reduced loading in weightlessness. Moreover, approximately 70% of astronauts experience space motion sickness to some degree during the first days. The drugs commonly used to combat motion sickness, such as scopolamine and promethazine, have soporific effects. These factors can lead to chronic fatigue. The challenge of integrative space medicine and physiology is to investigate the adaptation of the human body to spaceflight as a whole, and not just as the sum of body parts because all body functions are connected and interact with each other.
==History of space neuroscience==
To date, only three countries, the United States, Russia, and China, have the capability to launch humans into orbit. However, 520 astronauts from more than thirty different countries have flown in space and many of them have participated in space neuroscience research. The launch of the first living animal in orbit on Sputnik on November 3, 1957 marked the beginning of a rich history of unique scientific and technological achievements in space life sciences that have spanned more than fifty years to date.
The first documented space neuroscience experiments were performed during the third human mission on board the Russian Vostok spacecraft. These experiments began after the crew from previous missions complained from nausea and spatial disorientation in weightlessness. Space neuroscience experiments typically addressed these operational issues until the Skylab and Salyut space stations were made available for more fundamental research on the effect of gravity on CNS functions. Approximately 400 space neuroscience experiments have been performed from Vostok-3 in August 1962 to the Expedition-15 on board the International Space Station in October 2007.
抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』
■ウィキペディアで「Neuroscience in space」の詳細全文を読む
スポンサード リンク
| 翻訳と辞書 : 翻訳のためのインターネットリソース |
Copyright(C) kotoba.ne.jp 1997-2016. All Rights Reserved.
|
|