Blood Transport. Flashcards
How O2 is transported
: 99% bound to hemoglobin (Hb), Each g Hb can transport 1.34ml O2 (Max Saturation); Increased O2 delivery accomplished by increased cardiac output and redistribution of blood flow from inactive organs to working skeletal muscles
Males O2/L blood
150g Hb/L blood x 1.34ml O2/g Hb = 200 ml O2/L blood
Females O2/L blood
130g Hb/L blood x 1.34ml O2/g Hb = 174 ml O2/L blood
OxyHb Dissociation Curve
Deoxyhemoglobin + O2 < > Oxyhemoglobin; Direction of reaction depends on: PO2 of the blood and affinity between Hb and O2
OxyHb Dissociation Curve at Lung
High PO2, Formation of OxyHb
OxyHb Dissociation Curve at Tissues
Low PO2, Release if O2 to tissues
OxyMb Dissociation Curve
Shuttles O2 from the cell membrane to the mitochondria
Mb has a higher affinity for O2 than hemoglobin, even at low PO2, allows Mb to store O2 (O2 reserve for muscles)
When PaO2 drops below 60 mmHg in OxyMb Dissociation Curve
Myoglobin has a higher affinity for oxygen than does hemoglobin
This allows for a unidirectional transfer of O2 from hemoglobin (blood) to the myoglobin (muscle fiber)
How CO2 is transported
issolved in plasma (10%), Bound to Hb (20%), Bicarbonate (70%); CO2 + H2O > Carbonic Anhydrase > H2CO3 > H+ + HCO3-
How CO2 is transported at Lung
O2 binds to Hb (drives off H+), Reaction reverses to release CO2
How CO2 is transported at Tissue
H binds to Hb, HCO3- diffuses out of RBC into plasma, Cl- diffuses into RBC (chloride shift)