Resp 7 Flashcards
Physical factors alternating hemoglobin’s affinity for O2
- pH
- PCO2
- temperature
- 2,3-DPG
Bohr effect
shift in hemoglobin saturation as a result in pH or CO2 change
Lower pH effect on Hb’s affinity for O2
decreased affinity; more O2 delivery (v.v)
Decreased PCO2 effect on Hb’s affinity for O2
decreased PCO2 means less O2 delivered (v.v)
Temperature on altering Hb’s affinity for O2
Increased temp. means more O2 delivery
Hypoxia increases ___________- production
2,3 DPG
Higher altitudes mean…
low atmospheric PO2 and increased 2,3 DPG production
Decreased 2,3DPG on altering Hb’s affinity for O2
increased O2 release (lower affinity)
fetal Hb composed of…
2 alpha, two gamma globulin subunits
maternal/adult Hb composed of…
two alpha, 2 beta subunits
Why is it important to remove CO2 from the body?
-elevated PCO2 causes acidosis and depresses CNS
7% of CO2 is…
carried by venous blood and dissolved in plasma
23% of CO2 is…
binds to Hb
70% of CO2 is…
converted to bicarbonate (HCO3-)
What is the purpose of converting CO2 to HCO3-?
- provides additional means of CO2 transport from cells to lungs
- HCO3- can act as buffer to stabilize body’s pH
carbonic anhydrase
converts CO2 to HCO3-
To ensure equilibrium between conversion of CO2 to HCO3- and H+ is not reached, which two mechanisms exist?
-removal of HCO3- from RBC and Hb binding to excess H+ to prevent large changes in body’s pH and prevent acidosis
carbaminohemoglobin
formed when CO2 binds to free Hb at amino group
Formation of carbaminohemoglobin continues until..
PCO2 is equilibrated between cell, plasma, and RBC
When plasma CO2 diffuses into alveoli…
everything basically reverses.. (RESP 7, slide 20)
