Partial pressure of gases in various parts of the respiratory system

[scilearner]

Hello everyone,

 

Ok to understand the respiratory system, proper understanding of this diagram is essential. Something I don't have, so if anyone can help me with these questions I would be very greatful. Thanks

 

 

1. Anatomic dead space and residual volume?

I know what anatomic dead space is but residual volume is confusing me. Is it in the conducting zone as well and non technically isn't it like some kind of anatomic dead space.

 

2. Why does the alveoli have less partial pressure of oxygen than inspired air? I can understand how addition of water vapour can reduce it but residual volume just confused me. Does oxygen from residual volume get mixed with this as well increasing P02.

 

3. Why does the expired air have higher P02 of oxygen than alveoli?

I can understand how mixing with dead space would archieve it. Does the residual volume affect it as well. Residual volume is confusing me.

 

4. What creates the P02 in arterial blood and why it is 95?

So it is basically oxygen dissolved in blood right that causes the partial pressure of oxygen.We consider the haemoglobin bind oxygen as part of dissolved blood right? 95 is due to shunting right?

 

5. Why is PC02 in alveoli 40 and what creates PC02 in arterial blood?

Is it 40 in alveoli because CO2 diffuses into it from the capillaries. So C02 from tissues goes to capillarie-->veins--->capillaries---->alveoli so from where does arterial PC02 come from.

 

Your help would be greatly appreciated. Thanks

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Merged post follows:

Consecutive posts merged

The colour of blood for arteries and veins is mixed up in the diagram. So excuse that.

[greenprogrammin]

1. I believe the residual volume is the volume of air that will reside in the lungs during exhalation.

 

I think you should consider tidal volume and then residual volume.

 

I don't know the rest off the top...

Sorry...