Question

Gas Transport in the Blood. Describe in detail how carbon dioxide is transported in the blood. Be sure to include all the ways the blood transports carbon dioxide and a detailed explanation/description of how carbon dioxide is “loaded” and “unloaded” from the blood both in the tissues and the alveoli.

Answer 1

Carbon dioxide Transport:

*At Tissues-

At Tissues pCO2->45 mm Hg.In Oxygenated Blood-pCO2-40 mm Hg..

So there will be Diffusion of CO2 from the Tissue to Blood(From Area of High partial pressure to Low Partial Pressure)so there Is Loading of CO2 in the Blood.

The CO2 Loadd in the Blood is Transported to Lung ALveoli by -

CO2 in the tissues diffues into Blood,they are Transported to Lung Alveoli by-

1.dissolution directly into the blood:Some of CO2 can be Transported Dissolved in Plasma-About 7% can be Transported by this way

2. binding to hemoglobin:Some of the CO2 Bind to Hemoglobin in Blood at Tissues to Form HbCO2 which are Transported to Lung as Hb CO2 where it Dissocaites into Hb + CO2.This Transport occur About 23%

3.bicarbonate ion:Most of the Carbon Dioxide are Transported by this Way.(70%)

At Tissues,

CO2+H2O-------H2CO3--------HCO3- + H+.

CO2 are Transported as HCO3- into Lung

At Lung,

HCO3- + H+--------------------H2CO3------------H2O + CO2

HbCO2--------------------------Hb + CO2

All the CO2 unloads from the RBC and Diffuses into Lung.

At Lungs There is Unloading of CO2 from Blood,Because pCO2 at Lung Alveoli is 40 mmHg & pCO2 in Deoxygenated Blood reaching Lung is about 46 mm Hg...so There is Unloading of CO2 from Blood into Lung Alveoli.

*HCO3- + H+--------------------H2CO3------------H2O + CO2

*HbCO2--------------------------Hb + CO2