Quiz 5 Transport of O2 and CO2 Flashcards
Rate of CO2 production by cells
200 mL/min
Metabolic arteriovenous CO2 difference
40 mL/L
Metabolic arteriovenous O2 difference
50 mL/L
Rate of O2 use by cells
250 mL/min
Tissue PCO2
> 50 mmHg
Tissue PO2
> 10 mmHg
hypoxic hypoxia
inadequate O2 uptake in lungs
stagnant (ischemic) hypoxia
inadequate blood flow to an organ (arteriosclerosis, PVD, stroke, MI, bowel infarct)
anemic hypoxia
inadequate blood o2 carrying capacity
inactivated hemoglobin
histotoxic hypoxia
interference with mitochondrial respiration (like cyanide poisoning)
tissues have O2, but can’t use it
Normal Hb concentration?
15 g/dL
RBC carry ___ times more O2 than plasma
65
97% carried via Hbg
3% carried in plasma
How many subunits (or heme groups) does Hb have?
4 subunits= α2β2
4 subunits = 2 alpha + 2 beta
Amount of oxygen each gm of Hb can carry?
1.31 mL O2*
What shape is the HbO2 curve?
sigmoid
The ratio of O2 bound to Hb compared to total amount that can be bound is
Oxygen Saturation
Maximal amt of O2 bound to Hb is
Oxygen Capacity
***What is the Hb P50 point?
PaO2 is 27 when sat is 50!!!
reference point for when hemoglobin is 50% saturated
What is your PaO2 when the sat is 90
60
What is your PaO2 when the sat is 50?
27!
Rough rule for PaO2 to sat
40,50,60 for sat 70,80,90
The higher the affinity, the ___ the saturation
higher
The top of the curve represents
Oxygenated blood leaving the lungs
The middle of the curve represents
Capillaries
The starting point of the curve represents
Reduced blood returning from tissues
The x axis on curve
PaO2= pressure of oxygen in blood (mmHg)