Naked Science Forum

General Science => General Science => Topic started by: cat_with_no_eyes on 06/08/2010 19:50:27

Title: Are these 3 methods correct, excretion of co2?
Post by: cat_with_no_eyes on 06/08/2010 19:50:27

Are these 3 methods correct, of how co2 is taken back to the lungs to be excreted?


1 -tissue respiration

2 - ventilating the lung

3- gaseous exchange [???]

Title: Are these 3 methods correct, excretion of co2?
Post by: QuantumClue on 19/12/2010 00:10:11

Cat,

All three are required processes for CO2.

Title: Are these 3 methods correct, excretion of co2?
Post by: SteveFish on 19/12/2010 01:27:54

Cat_with_no_eyes:

O₂ is processed into CO₂ for respiration in mitochondria, an organelle which is present in every cell in the body. Both O₂ and CO₂ are small enough and have the correct properties to be able to dissolve directly through cellular membranes between cells and the blood. So at the periphery, your fingertip for example, where there is excess CO₂ and a need for O₂, the CO₂ dissolves down it's concentration gradient into blood vessels, while the excess O₂ in the blood dissolves out into the tissue. The CO₂ is complexed into insoluble HCO₃ inside red blood cells so that it can't dissolve out into other tissues before getting to the lungs, but at the lungs it is converted back into CO₂ so it can dissolve into the air in the lungs, and O₂ dissolves into the blood so it can be distributed to all the cells in the body. This is complicated but it works just fine.

Steve