The effects of short-term simulated microgravity on the cardiovascular system and cognitive function
LE3 .A278 2019
Bachelor of Kinesiology
Humans having the capability to travel to space has opened many doors and opportunities for new research concepts and understandings to occur. Space is a very unique environment, filled with harsh and challenging components. A main component of spaces’ environment that researchers are particularly interested in, especially in regards to its effect on physiological functions, is microgravity. Microgravity has been shown to impact many physiological systems, however, research surrounding short-term effects of microgravity on systems such as the cardiovascular system, cognition, and cerebral hemodynamics and cerebral oxygenation are scarce. In existing literature, the cardiovascular systems’ response to acute microgravity is nearly unvarying. Components of this system such as blood flow, blood pressure, cardiac output, heart rate and stroke volume have all been reported to change upon exposure. Significant changes in variables such as cardiac output, heart rate and stroke volume have been found, with all variables decreasing from baseline measures. There has been little research conducted on how cognitive performance is influenced by short-term microgravity. Researchers looking at cognition in acute microgravity have mostly focused on changes in executive function. Results of these studies have revealed that cognitive performances show either no differences from baseline testing, or improvements in acute exposure. Regarding cerebral hemodynamics, contradicting results appear in the available literature . Research has shown that cerebral blood flow either increases or decreases during short-term exposure to microgravity. With cerebral oxygenation, studies have shown a common result as oxygen in the brain tends to increase upon exposure to acute microgravity. Furthering knowledge in these areas of research at an acute level could allow for a greater understanding as to why some physiological conditions occur at a more chronic level. New insights to possible mechanisms of these outcomes could also occur. With space tourism quickly approaching, an in depth understanding of the effects of microgravity on human physiology is crucial. However, there are gaps within the literature, specifically within the domain of how short-term microgravity impacts the cardiovascular system and cognitive function. Therefore, the purpose of this project was to gain an understanding as to how the cardiovascular system and cognitive functions are impacted by short-term simulated microgravity. Using a -6° head-down-tilt methodology to simulate microgravity, twenty-three healthy young adults were tilted for an hour and a half. A cognitive test (Stroop Task) was completed pre and post an hour and a half to measure the effects of simulated microgravity of cognitive performance. Cardiovascular variables such as heart rate, stroke volume and cardiac output were also measured to understand microgravity’s impact. Significant findings occurred in the measured cardiovascular variables with all variables deceasing after exposure to an hour and a half of microgravity. Significant results were also found with the cognitive task, as improvements occurred in executive function post tilt. These results allow for an understanding as to what happens to these systems at an acute level of exposure to microgravity, also enabling possible mechanisms to be further investigated with regard to why these outcomes occurred.
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