通过研究发现,人的血液pH通常在7.35~7.45之间,变化不大的原因是 

通过研究发现,人的血液pH通常在7.35~7.45之间,变化不大的原因是                                                                  

①H2CO3/NaHCO3、NaH2PO4/Na2HPO4等多对缓冲物质对血液酸碱度起缓冲作用

②通过呼吸系统可不断排出CO2

③血浆中过多的碳酸氢盐可以由肾脏随尿排出体外

④神经系统对呼吸运动强度的调节有利于维持血液pH的相对稳定

⑤食物中的碱性物质与新陈代谢产生的酸性物质所构成的缓冲对调节了血液pH

A.只有①②                    B.只有①②③

C.只有①②③④                D.只有①②③⑤

答案

D

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