航天中的心血管问题

Cardiovascular Problems During Space Flight

人体的心血管系统具有向全身各组织、器官输送营养物质、排泄代谢产物、参与体液和电解质的调节、维持体内环境稳定的作用,并具有防御和保护功能。心血管系统是维持人体进行正常生理功能的重要系统,它的功能改变必然引起体内其它生理系统功能的紊乱。载人航天实践证明,轨道飞行中的微重力对心血管系统有明显的影响,可引起心血管功能失调。因而,微重力对心血管系统的影响及其防护措施的研究已成为航天医学研究中的一个重要课题。

Cardiovascular function is one of the main functions disturbed by microgravity. It was discussed in the following four areas:(1) Adaptive changes of cardiovascular system during microgravity. The following cardiovascular changes were observed during actual or simulated microgravity: increase of regular and central venous pressure, decrease of venous pressure in the legs, increase of intracranial pressure and blood volume,disorder in microcirculation and blood rheology ,orthostatic intolerance and impared exercise capacity. (2)Mechanism of cardiovascular deconditioning. The exact biologic mechanisms of the cardiovascular deconditioning responses have been established, the author suggests the following five factors as the main causes: reduction in plasma volume, changes in baroreactor reflex function, disorder in microcirculation and blood rheology, alterations in vessel compiance and capacity, muscle atrophy with decrease in pumping function. (3). Countermeasures. In this section,the countermeasures used in space flight were reviewed. (4)Suggestions for future research. Some of the fundamental unresolved questions were listed and the author put forward the opinion that future studies in China had better be focussed on the study of biological mechanism and the application of the traditional Chinese medicine in study of the countermeasures.