lung phys Flashcards
CO2 goes from tissue to plasma to RBC via_____?
diffusion
CO2 gets converted to______
H+ and HCO3
How does CO2 get back to the lungs?
HCO3 exchanges with Cl (chloride shift) and travels back to the lungs un the plasma
what happens to H+ after its dissociated from CO2 in the RBC?
gets buffered by DEoxyhemoglobin
better buffer than oxyhemoglobin
what happens when the CO2 gets to the lungs?
everything happens in reverse
xchange HCO3 for Cl –> HCO3 combines with H+ –> gets converted back into CO2 –> gets expired
mech of methemoglobinemia?
Fe2 binds O2
methemoglobin= Fe3 –> decrease SaO2
in anemia, why is total O2 decreased?
PAO2, PaO2, SaO2= normal
but LESS hgb, so less O2
less hgb doesn’t effect saturation
in CO, why do you see total O2 decreased?
Decrease SaO2
PAO2, PaO2= nl
CO occupies hgb binding sites
why does hypoventilation and COPD cause hypoxemia?
anything that causes inceased PACO2 wil cause a decreased PAO2 and thus dec PaO2
what happens in pulm vasc of newborn?
first breath DECREASES PULM VASC RES
central chemoreceptors are located in ________ and respond to __________?
peripheral chemoreceptors are located in _______ and respond to _________ by __________?
medulla –> decreasing pH (CO2 diffuses into CSF and dissociates into HCO3 and H+)
IC and AA –> respond to increase PaCO2, dec PaO2 and decrease pH –> will trigger hyperventilation
what lung values cannot be measured by spirometry?
RV, so TLC and FRC as well
You can measure VC by spirometry
what happens to intrapl;eural pressure during inspiration?
becomes MORE negative
what structure along the bronchial tree has the HIGHEST resistance? Why?
medium sized bronchi
alveoli are small but arranged in parallel so resistance is decreased
