In school, I have learnt that the deoxygenated blood brought in to the Alveoli by Pulmonary Arteries contains Carbon Dioxide. And that Carbon Dioxide present in the blood diffuses into the Alveoli and squeezed out with the help of Diaphragm.
Then, why doesn't the Nitrogen present in the Alveoli gets diffused to the blood? My guess was that the blood vessels don't allow anything other than CO2 and O2 to pass through.
But I recently saw a video on KhanAcademy where Sal said that some amount of Nitrogen does get mixed with blood. Is Sal right? If yes, then why doesn't the whole Nitrogen present in the Alveoli gets diffused from there (where it is present in high concentration) to blood (where it is present in low concentration)?
- Why doesn't the inhaled-Nitrogen present in the Alveoli diffuses into the blood present in Pulmonary Veins, similar to how CO2 present in blood gets diffused out to the Alveoli?