Transport of Carbon Dioxide

What is the first step in carbon dioxide transport from tissues?

CO2 diffuse out of cells into systemic capillaries

Approximately what percentage of CO₂ is transported dissolved in plasma? (phase 2)

7%

What happens to about one-fourth of CO₂ in the blood? (phase 3)

CO2 binds to hemoglobin, forming carbaminohemoglobin

What percentage of CO₂ is converted into bicarbonate (HCO₃⁻)? (phase 4)

70%

What role does hemoglobin play in CO₂ transport when H⁺ is produced? (phase 4)

Hemoglobin buffers H+

What is the chloride shift? (phase 5)

Exchange of HCO₃^- out of RBCs for Cl ^- into RBCs

What happens to dissolved CO₂ at the lungs? (phase 6)

Dissolved CO2 diffuses out of the plasma

What occurs to CO₂ bound to hemoglobin in the lungs? (phase 7)

It unbinds and diffuses out of the RBC

What happens to bicarbonate (HCO₃⁻) reaction reverses in the lungs?

It pulls back into RBC and converts back to CO₂