Question

The partial pressures (in $mm Hg$ ) of oxygen $\left( O _{2}\right)$ and carbon dioxide $\left( CO _{2}\right)$ at alveoli (the site of diffusion) are:

• A. $pO _{2}=104$ and $pCO _{2}=40$
• B. $pO _{2}=40$ and $pCO _{2}=45$
• C. $pO _{2}=95$ and $pCO _{2}=40$
• D. $pO _{2}=159$ and $pCO _{2}=0.3$

Answer 1

Answer: (A)

In the alveolar air, the partial pressures of oxygen $\left( pO _{2}\right)$ is $104\, mm\,Hg$ and that of carbon dioxide $\left( pCO _{2}\right)$ is $40\, mm\,Hg$.