Exam 3: Gas Transport Flashcards
TISSUE LEVEL: #1
Where does CO2 come from?
Where does it go?
Metabolism.
Most diffuses over into RBC, some into the plasma
TISSUE LEVEL: #2
What happens to the CO2 in the RBC?
Some stays dissolved, some gets converted into carbamino compounds, MOST turns into bicarb
TISSUE LEVEL: #3
How does CO2 get converted into bicarb?
What enzyme helps?
CO2 and H20 get converted into H2CO3 (carbonic acid) and then into H+ and HCO3
Carbonic anhydrase
TISSUE LEVEL: #4
Where does bicarb go?
Through what process?
Bicarb leaves to plasma to be a buffer.
Gets exchanged for one Cl- via bicarb/Cl exchanger.
Cl will hang out in Hb till it reaches the lungs
TISSUE LEVEL: #5
Where does the H+ that was formed go?
Once oxyhemoglobin unloads O2 to tissues, now deoxyhemoglobin it becomes a great acceptor for the H+
TISSUE LEVEL: #6
What facilitates oxygen unloading?
What indicator causes oxygen unloading?
Tissue demands facilitate O2 unloading as decreased O2 levels are sensed and more O2 is unloaded.
Decreased pH and increased CO2 is sensed and more O2 is unloaded. Remember that decreased pH and increased CO2 decrease O2 affinity, leading to more unloaded.
TISSUE LEVEL: #7
What happened to that proton that binded with hemoglobin?
It attaches some CO2 to itself to make it a carbamino compound.
LUNG LEVEL: #1
Where does the CO2 go?
How?
CO2 diffuses over into alveoli.
The PCO2 of the lung air is 40 and the blood is 45, this causes a [ ] gradient for CO2 to diffuse over
LUNG LEVEL: #2
Where does this CO2 come from?
Dissolved state from the tissues.
CO2 falls off from the carbamino compounds to get expelled.
Bicarb
LUNG LEVEL: #3
Where do the protons go from this broken down carbamino group?
What are the products of this reaction?
What helps this reaction?
Protons from buffered deoxyhemoglobin combines with bicarb to make carbonic acid.
CO2 and water from the formation of carbonic acid from the H+ and bicarb.
Carbonic anhydrase
LUNG LEVEL: #4
Bicarb is being used to help generate CO2 to be expelled. How do we compensate for this?
Bicarb from the plasma is exchanged for a Cl-. Bicarb moves into the RBC and Cl- into the plasma.
LUNG LEVEL: #5
What happened to the proton?
The proton fell of the deoxyhemoglobin. This less acidic environment increases O2 affinity.
LUNG LEVEL: #6
What happens to the Hb now?
Now that the proton fell off, the Hb can be onloaded with O2. O2 diffuses over from the lungs to the RBC.
LUNG LEVEL: #7
What happened to these carbamino compounds?
Since we are trying to expel CO2 this encourages these compounds to fall apart so the CO2 can be expelled.
