Chapter 22: O2/CO2 Transport/Oxyhemoglobin Dissociation Curve

saturation

the percentage of Hb that is bound to O2

loading of O2

occurs because of a shape change of Hb

oxyhemoglobin dissociation curve

Relationship between available oxygen and amount of oxygen carried by hemoglobin.

PO2 100mmHg in the lungs

98% Hb saturation

lower arterial PO2 leads to

oxygen leaving Hb

PO2 40mmHg in resting tissues

75% Hb Saturation

PO2 20mmHg in active tissues

40% Hb Saturation

high arterial PO2 favors

O2 binding to Hb

with a O2-Hb dissociation curve shifts right

Increased temperature and CO2 and decreased pH

with a O2-Hb dissociation curve shifts left

decreased temperature and CO2 and increased pH

Bohr Effect

Declining blood pH (acidosis) and increasing PCO2 cause Hb-O2 bind to weaken

heat production in active tissues cases

decreased Hb affinity for O2

CO2 is transported in the blood in three forms

1.) 7 to 10% dissolved in plasma.

2.) 20% bound to globin of hemoglobin (carbaminohemoglobin).

3.) 70% transported as bicarbonate ions (HCO3-) in plasma.

Haldane effect

the lower the PO2 and hemoglobin O2 saturation, the more CO2 can be carried in the blood

slow shallow breathing

increased CO2 in blood and a drop in pH

rapid deep breathing

decreased CO2 in blood and a rise in pH